Slave of Bolas

Gain control of target creature. Untap that creature. It gains haste until end of turn. Sacrifice it at the beginning of the next end step.

Tetsuo, Imperial Champion

Whenever Tetsuo attacks, if it's equipped, choose one —
• Tetsuo deals damage equal to the greatest mana value among Equipment attached to it to any target.
• You may cast an instant or sorcery spell from your hand with mana value less than or equal to the greatest mana value among Equipment attached to Tetsuo without paying its mana cost.