If Guardian Kirin and another creature you control die simultaneously (perhaps because they were both attacking or blocking), Guardian Kirin won't be on the battlefield as its triggered ability resolves. It can't be saved by the +1/+1 counter that would have been put on it.
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.