Sigil of the New Dawn
Enchantment
Whenever a creature is put into your graveyard from the battlefield, you may pay 
. If you do, return that card to your hand.
The sigil represents an honor that endures beyond death.
Volkan Baǵa
Ultimate Masters (UMA)
• #35Rulings
Sigil of the New Dawn's ability triggers if a creature you own dies under another player's control.
(wotc • 2018-12-07)
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.
(wotc • 2018-12-07)
Rulings
Sigil of the New Dawn's ability triggers if a creature you own dies under another player's control.
(wotc • 2018-12-07)
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.
(wotc • 2018-12-07)