Quote from LordOfTexasSaying he's the best finisher possible is a tricky use of words. This guy is excellent in creature-light control mirrors, where you just need a large threat to stick so you can end the game.
However, finishers are about more than resilience and damage output. They are also about catching you up from behind, which this guy does not do very well. He has no lifegain and no board impact other than being a 4/5. If you blink him in response to removal, then he can't block that turn either.
Not saying he's unplayable, just that he's only great in certain matchups. The bar for 7 drops is really high in cube - I'm not sure if he makes the cut in my 450 unpowered list.