When a creature you control dies, each opponent loses a life and you gain one
Quakebringer will deal plenty of damage to your opponents, even if its in your graveyard
What really does it for me is the decent power on a snake that is already a naturally recursive creature
Low Equip cost: The lower your Equip cost, the easier it is to arm a creature and/or move your equipment to other creatures, perhaps even after combat
Doublers Like the previously mentioned Throne, there are all sorts of ways to double things, whether thats doubling ETB triggers with Panharmonicon effects, counter doubling, token doubling like Doubling Season, or even creature doublers like Reflections of Littjara
Sephiroth, Fabled SOLDIER / Sephiroth, One-Winged Angel Death triggers and life loss go hand in hand, and they rarely look better than on Sephiroth, Fabled SOLDIER