The Mourning Knight

Flash
Whenever another creature you control dies, or is destroyed, or exiled by a spell or ability an
opponent controls, you gain {e}
Whenever another creature or planeswalker you control would take damage, you may pay X {e}. to reduce that damage by X.
partner with The Knight's Lost Lover.
If The Knights Lost Lover enters the battlefield while this card is on the battle field, return this to the command zone without increasing it's mana cost.