Necrosynthesis

Enchant creature Enchanted creature has "Whenever another creature dies, put a +1/+1 counter on this creature." When enchanted creature dies, look at the top X cards of your library, where X is its power. Put one of those cards into your hand and the rest on the bottom of your library in a random order.

From Magic: The Gathering.

Open the interactive version on https://mythscribe.cloud/app/tcg/cards/cms6okiokev7ppb1hgwl9spl8.