Does this work?

A list of comments:

1) The rules for entwine would have to be rewritten slightly, I think, for this to work.
2) The fact that this can target itself with that second ability seems quite powerful to me.
3) The life gain in the second ability is neither blue or black.
4) This has no power or toughness

I think the lifegain in the second ability does kinda work on a gold card, though. It's like Sever Soul but doing a blue thing to the creature rather than a black thing. ...Oh, hang on, it only targets your own creatures? Oh, no, that's not black then. I think it'd be okay on opponents' creatures though.

That first ability is way, way better than the second, though. It's Twisted Justice but targeted. Not only is drawing cards much better than gaining life, but destruction is better than bouncing your own stuff in most cases.

Yeah, it was originally "kill an enemy creature and gain life or bounce your creature and draw cards" -- a black ability and a blue ability respectively. Then I decided to swap bits of it. The bounce-draw is incredibly powerful though, you are correct. Especially since I forgot to make it "another" creature. Considering that I also forgot to give it P/T, I'm guessing I was just really distracted when I made this.

Bouncing your own stuff as an ETB does show up in blue often enough (see Quickling) though I'll admit that it does show up more often in white or green--

Hang on, that gives me an idea.

There we go. I also removed the Entwine. It's a pity that it doesn't work within the rules -- which I guessed it wouldn't but had hoped otherwise -- but I kind of like this design as well.