Aaron, Quickfire Breachmage

Twincast — Whenever you cast an instant spell
from your hand, put a pulse counter on Aaron,
Quickfire Breachmage. If that spell is your fourth
instant spell cast this turn, copy that spell. You may choose new targets for the copy.

Straight Flush — {t}, Remove four pulse counters
from Aaron and reveal your hand: Create a copy of
each instant card with mana value 4 or less revealed
this way. You may cast those copies.