Giving either creature first strike does not affect the ability.
04-10-2004
wotc
If this leaves the battlefield before its activated ability resolves, it will still deal damage to the targeted creature. On the other hand, if the targeted creature leaves the battlefield before the ability resolves, the ability won't resolve and no damage will be dealt.
Random a card of Magic: The Gathering (MTG), but you can also roll the D20 dice, random a Planeswalker, have fun with the random rules and more.