Vampiric Scepter

Forge (You may cast this spell by sacrificing any number of equipments and paying this card mana cost reduced by those equipments converted mana cost.)
Armed creature gets +1/+1.
Arm {1} ({1}: Attach to target legendary creature you control as a sorcery. When a legendary creature you control enters the battlefield, you may arm as an instant. As long as this ability is on the stack, your opponent can't cast spells or activate abilities.)