Magnito, Master of Metal

+3: Create a token of an unregistered mutant. If you control 5 or more mutants gain Brotherhood Emblem with "each mutant has hexproof and +1/+1 once"
-X: Gain control of target artifact with a mana value X or less.
-8: Each oponent sacrifices all artifacts they control then takes 3 damage divided as you choose among players/creatures for each artifact sacrificed