Hmm, that looks pretty strong. Each creature of yours comes with a bonus 4 life. Quite effective in limited. Not overpowered, though; the game needs some powerful effects (and I prefer them to be like this, "quite strong" not "utterly game-changing"). Might be more suited for uncommon at its current power level, though.

this should be good, I really like this pairing of abilities, and the black activation makes it really feel right.

Only thing is that it might be too strong. Really, like sac your whole board to hit everyone for ten? Even if you only sac five guys with this that's 15 damage dealt and 5 gained. Although I guess the flipside is that you'd be leaving yourself open to an attack if you sac all your dudes. I dunno, might need testing or perhaps more mana in the activation cost to balance it.

This is a really interesting card. I like it a lot. I fear it may be more suited for uncommon than rare, but it's a very interesting pair of abilities.

Yeah I have this thing about designing commons and having to bump them to uncommon.

Also added a tap feature so you cant's just chain your one token into as many life as you have black mana.

"designing commons and having to bump them to uncommon" - Heh, well, it seems you're not alone. MaRo said in a recent article (I think it was his recent Nuts & Bolts article) that "One way I get uncommons for the design file is I ask my team to design commons". :)