Chei'Lar Espelon

Chei’lar gets +1/+1 for each card you own that’s in exile.

At the beginning of your upkeep, exile the top X cards of your library, where X is Chei’lar’s power. You may play those cards this turn.

{t}, Sacrifice Chei’lar: Add X mana of any one color, where X is Chei’lar’s power. Spend
this mana only to cast cards from exile.