diff --git a/python/src/trezorlib/client.py b/python/src/trezorlib/client.py
index 8a3fff6d10..2c017a58d3 100644
--- a/python/src/trezorlib/client.py
+++ b/python/src/trezorlib/client.py
@@ -116,7 +116,7 @@ class TrezorClient:
 
         if isinstance(self.protocol, ProtocolV1Channel):
             return SessionV1.new(self, passphrase, derive_cardano)
-        raise NotImplementedError  # TODO
+        raise NotImplementedError
 
     def resume_session(self, session: Session):
         """
diff --git a/python/src/trezorlib/debuglink.py b/python/src/trezorlib/debuglink.py
index 0067d644c1..ccfa67f682 100644
--- a/python/src/trezorlib/debuglink.py
+++ b/python/src/trezorlib/debuglink.py
@@ -798,7 +798,7 @@ class DebugUI:
 
     def clear(self) -> None:
         self.pins: t.Iterator[str] | None = None
-        self.passphrase = ""
+        self.passphrase = None
         self.input_flow: t.Union[
             t.Generator[None, messages.ButtonRequest, None], object, None
         ] = None
@@ -848,7 +848,7 @@ class DebugUI:
         except StopIteration:
             raise AssertionError("PIN sequence ended prematurely")
 
-    def get_passphrase(self, available_on_device: bool) -> str:
+    def get_passphrase(self, available_on_device: bool) -> str | None | object:
         self.debuglink.snapshot_legacy()
         return self.passphrase
 
@@ -1098,7 +1098,6 @@ class SessionDebugWrapper(Session):
         self.button_callback = self.client.button_callback
         self.pin_callback = self.client.pin_callback
         self.passphrase_callback = self._session.passphrase_callback
-        self.passphrase = self._session.passphrase
 
     def __enter__(self) -> "SessionDebugWrapper":
         # For usage in with/expected_responses
@@ -1232,7 +1231,6 @@ class TrezorClientDebugLink(TrezorClient):
         # and know the supported debug capabilities
         self.debug.model = self.model
         self.debug.version = self.version
-        self.passphrase: str | None = None
 
     @property
     def layout_type(self) -> LayoutType:
@@ -1328,12 +1326,16 @@ class TrezorClientDebugLink(TrezorClient):
                 return send_passphrase(None, None)
 
             try:
-                if session.passphrase is None and isinstance(session, SessionV1):
+                if isinstance(session, SessionV1) or isinstance(
+                    session, SessionDebugWrapper
+                ):
                     passphrase = self.ui.get_passphrase(
                         available_on_device=available_on_device
                     )
+                    if passphrase is None:
+                        passphrase = session.passphrase
                 else:
-                    passphrase = session.passphrase
+                    raise NotImplementedError
             except Cancelled:
                 session.call_raw(messages.Cancel())
                 raise
@@ -1387,33 +1389,6 @@ class TrezorClientDebugLink(TrezorClient):
             passphrase = Mnemonic.normalize_string(passphrase)
         return super().get_session(passphrase, derive_cardano, session_id)
 
-    def set_filter(
-        self,
-        message_type: t.Type[protobuf.MessageType],
-        callback: t.Callable[[protobuf.MessageType], protobuf.MessageType] | None,
-    ) -> None:
-        """Configure a filter function for a specified message type.
-
-        The `callback` must be a function that accepts a protobuf message, and returns
-        a (possibly modified) protobuf message of the same type. Whenever a message
-        is sent or received that matches `message_type`, `callback` is invoked on the
-        message and its result is substituted for the original.
-
-        Useful for test scenarios with an active malicious actor on the wire.
-        """
-        if not self.in_with_statement:
-            raise RuntimeError("Must be called inside 'with' statement")
-
-        self.filters[message_type] = callback
-
-    def _filter_message(self, msg: protobuf.MessageType) -> protobuf.MessageType:
-        message_type = msg.__class__
-        callback = self.filters.get(message_type)
-        if callable(callback):
-            return callback(deepcopy(msg))
-        else:
-            return msg
-
     def set_input_flow(
         self, input_flow: InputFlowType | t.Callable[[], InputFlowType]
     ) -> None:
@@ -1545,27 +1520,11 @@ class TrezorClientDebugLink(TrezorClient):
         """
         self.ui.pins = iter(pins)
 
-    def use_passphrase(self, passphrase: str) -> None:
-        """Respond to passphrase prompts from device with the provided passphrase."""
-        self.passphrase = passphrase
-        self.ui.passphrase = Mnemonic.normalize_string(passphrase)
-
     def use_mnemonic(self, mnemonic: str) -> None:
         """Use the provided mnemonic to respond to device.
         Only applies to T1, where device prompts the host for mnemonic words."""
         self.mnemonic = Mnemonic.normalize_string(mnemonic).split(" ")
 
-    def _raw_read(self) -> protobuf.MessageType:
-        __tracebackhide__ = True  # for pytest # pylint: disable=W0612
-        resp = self.get_seedless_session()._read()
-        resp = self._filter_message(resp)
-        if self.actual_responses is not None:
-            self.actual_responses.append(resp)
-        return resp
-
-    def _raw_write(self, msg: protobuf.MessageType) -> None:
-        return self.get_seedless_session()._write(self._filter_message(msg))
-
     @staticmethod
     def _expectation_lines(expected: list[MessageFilter], current: int) -> list[str]:
         start_at = max(current - EXPECTED_RESPONSES_CONTEXT_LINES, 0)
diff --git a/tests/click_tests/test_passphrase_delizia.py b/tests/click_tests/test_passphrase_delizia.py
index fc7d79610e..e0b9fbb91c 100644
--- a/tests/click_tests/test_passphrase_delizia.py
+++ b/tests/click_tests/test_passphrase_delizia.py
@@ -98,7 +98,6 @@ def prepare_passphrase_dialogue(
 ) -> Generator["DebugLink", None, None]:
     debug = device_handler.debuglink()
     device_handler.run_with_session(get_test_address)  # type: ignore
-    # TODO
     assert debug.read_layout().main_component() == "PassphraseKeyboard"
 
     # Resetting the category as it could have been changed by previous tests
diff --git a/tests/conftest.py b/tests/conftest.py
index 01d11e3b22..6cb5d1b6f2 100644
--- a/tests/conftest.py
+++ b/tests/conftest.py
@@ -364,9 +364,6 @@ def _client_unlocked(
         if request.node.get_closest_marker("experimental"):
             apply_settings(session, experimental_features=True)
 
-        if use_passphrase and isinstance(setup_params["passphrase"], str):
-            _raw_client.use_passphrase(setup_params["passphrase"])
-
         # TODO _raw_client.clear_session()
 
     yield _raw_client
@@ -391,7 +388,10 @@ def session(
         session = _client_unlocked.get_seedless_session()
     else:
         derive_cardano = bool(request.node.get_closest_marker("cardano"))
-        passphrase = _client_unlocked.passphrase or ""
+        passphrase = ""
+        marker = request.node.get_closest_marker("setup_client")
+        if marker and isinstance(marker.kwargs.get("passphrase"), str):
+            passphrase = marker.kwargs["passphrase"]
         if _client_unlocked._setup_pin is not None:
             _client_unlocked.use_pin_sequence([_client_unlocked._setup_pin])
         session = _client_unlocked.get_session(
diff --git a/tests/device_handler.py b/tests/device_handler.py
index 605b160c98..c060a405e9 100644
--- a/tests/device_handler.py
+++ b/tests/device_handler.py
@@ -64,8 +64,8 @@ class BackgroundDeviceHandler:
             raise RuntimeError("Wait for previous task first")
 
         # wait for the first UI change triggered by the task running in the background
+        session = self.client.get_session()
         with self.debuglink().wait_for_layout_change():
-            session = self.client.get_session()
             self.task = self._pool.submit(function, session, *args, **kwargs)
 
     def run_with_provided_session(
diff --git a/tests/device_tests/test_msg_loaddevice.py b/tests/device_tests/test_msg_loaddevice.py
index 89e9ebe4df..57c8459e9e 100644
--- a/tests/device_tests/test_msg_loaddevice.py
+++ b/tests/device_tests/test_msg_loaddevice.py
@@ -124,7 +124,6 @@ def test_load_device_utf(client: Client):
         skip_checksum=True,
     )
     session: Session = session.client.get_session(passphrase=passphrase_nfkd)
-    session.client.use_passphrase(passphrase_nfkd)  # TODO is needed?
     address_nfkd = get_test_address(session)
 
     device.wipe(session)
@@ -139,7 +138,6 @@ def test_load_device_utf(client: Client):
         skip_checksum=True,
     )
     session = client.get_session(passphrase=passphrase_nfc)
-    session.client.use_passphrase(passphrase_nfc)  # TODO is needed?
     address_nfc = get_test_address(session)
 
     device.wipe(session)
@@ -154,7 +152,6 @@ def test_load_device_utf(client: Client):
         skip_checksum=True,
     )
     session = client.get_session(passphrase=passphrase_nfkc)
-    session.client.use_passphrase(passphrase_nfkc)  # TODO is needed?
     address_nfkc = get_test_address(session)
 
     device.wipe(session)
@@ -169,7 +166,6 @@ def test_load_device_utf(client: Client):
         skip_checksum=True,
     )
     session = client.get_session(passphrase=passphrase_nfd)
-    session.client.use_passphrase(passphrase_nfd)  # TODO is needed?
     address_nfd = get_test_address(session)
     assert address_nfkd == address_nfc
     assert address_nfkd == address_nfkc
diff --git a/tests/device_tests/test_session.py b/tests/device_tests/test_session.py
index 9c8dfb924f..e8df254129 100644
--- a/tests/device_tests/test_session.py
+++ b/tests/device_tests/test_session.py
@@ -146,7 +146,6 @@ def test_session_recycling(client: Client):
                 messages.Address,
             ]
         )
-        client.use_passphrase("TREZOR")
         _ = get_test_address(session)
         # address = get_test_address(session)
 
diff --git a/tests/device_tests/test_session_id_and_passphrase.py b/tests/device_tests/test_session_id_and_passphrase.py
index c8a4b3c36c..93ce1eeb45 100644
--- a/tests/device_tests/test_session_id_and_passphrase.py
+++ b/tests/device_tests/test_session_id_and_passphrase.py
@@ -19,7 +19,6 @@ import random
 import pytest
 
 from trezorlib import device, exceptions, messages
-from trezorlib.client import ProtocolVersion
 from trezorlib.debuglink import LayoutType
 from trezorlib.debuglink import SessionDebugWrapper as Session
 from trezorlib.debuglink import TrezorClientDebugLink as Client
@@ -54,7 +53,6 @@ SESSIONS_STORED = 10
 def _get_xpub(
     session: Session,
     expected_passphrase_req: bool = False,
-    passphrase_v1: str | None = None,
 ):
     """Get XPUB and check that the appropriate passphrase flow has happened."""
     if expected_passphrase_req:
@@ -66,11 +64,6 @@ def _get_xpub(
         ]
     else:
         expected_responses = [messages.PublicKey]
-    if (
-        passphrase_v1 is not None
-        and session.protocol_version == ProtocolVersion.PROTOCOL_V1
-    ):
-        session.passphrase = passphrase_v1
 
     with session:
         session.set_expected_responses(expected_responses)
@@ -228,7 +221,6 @@ def test_max_sessions_with_passphrases(client: Client):
         _get_xpub(
             resumed_session,
             expected_passphrase_req=True,
-            passphrase_v1="whatever",
         )  # passphrase is prompted
 
 
@@ -435,7 +427,6 @@ def test_hide_passphrase_from_host(client: Client):
                 messages.PublicKey,
             ]
         )
-        client.use_passphrase(passphrase)
         result = session.call(XPUB_REQUEST)
         assert isinstance(result, messages.PublicKey)
         xpub_hidden_passphrase = result.xpub
@@ -471,7 +462,6 @@ def test_hide_passphrase_from_host(client: Client):
                 messages.PublicKey,
             ]
         )
-        client.use_passphrase(passphrase)
         result = session.call(XPUB_REQUEST)
         assert isinstance(result, messages.PublicKey)
         xpub_shown_passphrase = result.xpub
diff --git a/tests/upgrade_tests/test_firmware_upgrades.py b/tests/upgrade_tests/test_firmware_upgrades.py
index 49cd73d6c8..7a0bee8887 100644
--- a/tests/upgrade_tests/test_firmware_upgrades.py
+++ b/tests/upgrade_tests/test_firmware_upgrades.py
@@ -384,7 +384,7 @@ def test_upgrade_shamir_backup(gen: str, tag: Optional[str]):
         address = btc.get_address(session, "Bitcoin", PATH)
         if session.protocol_version == ProtocolVersion.PROTOCOL_V1:
             session.call(messages.Initialize(new_session=True))
-        new_session = emu.client.get_session(passphrase="TREZOR")
+        new_session = Session(emu.client.get_session(passphrase="TREZOR"))
         address_passphrase = btc.get_address(new_session, "Bitcoin", PATH)
 
         assert emu.client.features.backup_availability == BackupAvailability.Required