Ideas

Kaine's version of Scarlet Spider is an ex-con/killer struggling to reform himself...at least a little bit.
He's got retractable claws, a spike that comes out of his wrist, organic webbing, as well as an acidic touch and a slower version of wolverines ability to heal from damn near anything...This guy has died a couple of times and come back from it unscathed.
In addition to that he has all of Spider-Man's powers. The ability to lift up to two tons, jumping around 60 feet, Spider-Sense (the ability to sense incoming danger from any direction), and reflexes 40 times that of a normal persons...as well as extra durability and agility...and of course the ability to cling to any surface.
The Symbiont Suit is itself a living organism and can communicate with it's host (though normally it does so on a subconscious level) feeds off of adrenaline, can change any shape or color (even becoming transparent as a cloaking method), it can also change it's density.
It does come with some weaknesses though, Sonic Energy and Fire.