Onslaught
Onslaught is a hard boss to deal with. If a human is using him, he can be the cheapest thing alive.
Special Attacks
First Form
Hyper Gravitation - DPM+P
Magnetic Tempest - QCF+P
"Face My Wraith" - QCF+K
Sentinel Helper - MP+MKV
Sentinel Air Strike - Any Single Button
Teleport - HCB+K (WK = Left Side of Screen. MK = Middle of Screen. FK = Right Side of Screen.)
Second Form
Hyper Gravitation - DPM+P
Sentinel Air Strike - Any K
Fist Swing - Any P
Eye Beam Disruptor - QCF+P
"Behold By Might Hand" - QCB+K
Super Attacks
First Form
Magnetic Shockwave - QCF+2K
"Feel My Pain and Anger" - QCF+2P
Psionic Puppet - HCB+2K (Level 2) (Makes a clone of the person that you are facing currently. Onslaught heals himself in the background like if he was resting. The partner has 1/6 of the normal health and only stays out for a certain amount of time.)
Second Form
Mulitple Eye Beam Disruptors - QCF+2P
Combos
First Form
Any Button+Any Attack
This is a easy thing to do. Call a Sentinel Air Strike and then hit them with something else.
QCF+K, QCF+2K
This takes one super. First, use a "Face My Wraith". Then, right after it finishes, you can get an extra hit in by using a Magnetic Shockwave. It's a waste of a super, but it might be all that you need to kill the person.
Second Form
DPM+P, (QCF+P)
This is an infinite and the only proper combo that this guy has. All you have to do is catch them with one Hyper Grav. and then start using Eye Beam Disruptors. You must time the Eye Beam Disruptors properly or you will end up doing a Fist Swing instead.