Zni, Chaos Bringer

At the beginning of combat on your turn, you
may have Zni deal damage to each player, or each creature equal to the number of lands you control.
Any player dealt damage by Zni exiles the top X cards of their library, where X is the amount of damage dealt by Zni.
Players may play cards Exiled by Zni, and may
pay mana as though it were any
color to do so.