The enters-the-battlefield ability can target Armament Corps itself.
20-09-2014
wotc
You choose how the counters will be distributed as you put the ability on the stack. Notably, if you choose to put one +1/+1 counter on each of two target creatures, and one of those creatures becomes an illegal target in response, the +1/+1 counter that would’ve gone on that creature is lost. It can’t be put on the remaining legal target.
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.