Bruv

Constrain (When a player deals combat damage to
you, you may reveal this card from your hand. If
you do, you don't take combat damage and
attacking creatures don't at their next untap
step. Then, shuffle this card into you library.)
{w}{u}: Damage dealt to you will be redirected
to it's original dealer until the end of your turn
{b}: Deal 4 damage to target player