Whenever a nontoken, non-Angel creature you control dies, return that card to the battlefield under its owner’s control with a +1/+1 counter on it. It has flying and is an Angel in addition to its other types.
If Valkyrie's Call goes to the graveyard at the same time as one or more nontoken, non-Angel creatures you control die, its ability triggers once for each of those creatures.
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.