Conversation so far:
who was the man stick was talking to in daredevil
The guy Stick was talking to at the end of the episode is almost certainly Stone, who first appeared in Daredevil #187.
who did stick train on daredevil
Stick trained a young Matt Murdock how to fight and protect himself.

Question: who played that character
Self-contained rewrite: who played Stone in Daredevil