Anax and Cymede

Oracle Text

First strike, vigilance

Heroic — Whenever you cast a spell that targets Anax and Cymede, creatures you control get +1/+1 and gain trample until end of turn.

Card Rulings

9/15/2013 Only creatures you control when the heroic ability resolves will get the bonuses. Creatures that come under your control later in the turn will not.
9/15/2013 Heroic abilities will resolve before the spell that caused them to trigger.
9/15/2013 Heroic abilities will trigger only once per spell, even if that spell targets the creature with the heroic ability multiple times.
9/15/2013 Heroic abilities won’t trigger when a copy of a spell is created on the stack or when a spell’s targets are changed to include a creature with a heroic ability.