Sigil of the New Dawn's ability triggers if a creature you own dies under another player's control.
07-12-2018
wotc
If a creature you own dies at the same time that Sigil of the New Dawn leaves the battlefield, Sigil of the New Dawn's ability triggers for that creature.
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.