I need to know?

[Dark_Paladin_X]

[quoteost_uid0="theendbringer"]Hey i wanna noe can u unlock onslaught and if youcan den how can u?[/quote]
You CANNOT unlock onslaught. You can only choose him (under certain conditions) in the game.

1st Method

1on1, NOT TAG
first player MUST choose Venom as a helper (press k1 k2 k3)
the second player MUST pick Spiral as a helper (p1 k1)

2nd Method

2on1 TAG
You MUST be alone in the 2on1.
You (sometimes) MUST pick Sentinal as one of your 2 characters.
You MUST pick hulk as your helper (k1 p2 k3)

(If i'm not allowed to post this, then i'll delete it).