Factor in that reanimator decks typically want to bring back the biggest, baddest creatures of Magic s history as quickly as possible, and the pressure youll be applying through Chainer, Nightmare Adept will make you a quick believer of this simple truth
Once per Chain, when a Monster Card your opponent controls activates its effect (Quick Effect): You can either detach 2 materials from this card, or destroy 1 "Dark Contract" card you control, and if you do, attach that opponent's card to this card as material
If you clean the board a few times in a game, the board is going to be populated with smaller numbers of larger creatures, and making what sticks go away and getting some life out of it gives you more time to keep going on to your next big spell
In Magic, preconstructed decks built for the Commander deck are common, and are often released alongside major set releases (and in some cases, on their own)
The extra damage over two mana burn that you get really isn't worth that extra mana