Lordsphere

Spend only colored mana to cast Lordsphere.
Exile up to one target colorless permanent
or spell. Exile Lordsphere.
Prism - For each color of mana spent to cast Lordsphere -
{w}, {g} - You gain 1 life.
{u} - Look at the top card of each player's library.
{b}, {r} - Deal 1 damage to each opponent.