What part of your game you think puzzles help?

Well it really depends on the puzzle, doesn't it?  They're generally tactical but I've also seen positional puzzles and some that are focused on endgame technique.  I'm persaonlly a huge fan of retrograde which is probably a minimally relevant skill when it comes to actually helping your game.

Complicated games.. Middle games, Tactical openings and sometimes endgames where you sac a piece to mate

All but the opening.

they help me see things i might otherwise miss

the part where I miss things,or moves.