V.Sion's gameplay can be broken into 3 very simple phases.
Phase 1: Score a knockdown.
This phase differs based on the opponent you are fighting. The goal is to either land a CH j.A into a small bnb + airthrow, or exploit their mistakes to land a direct hit to bnb. This phase gets better with matchup experience and understanding of which of your pokes will force easy counter hits or beat them out during their positioning/zoning gaps.
Phase 2: Exploit your knockdown and attack.
Here are where your many frame neutral/frame advantage attacks come into play. 2B or 5B as meaties will defeat poor wakeup attacks. You can use j.AC or IAD C mixup. 236B or 236A xx 236C can be used when you are running out of normals to pin them down, as can whiff cancelling early and dashing or IADing back in. You also have to master 'Passive' rushdown. Bait their activation or wakeup ex. Exploit when they will jump out and j.A to land a clean hit or force them into a possible guard break. Throw people who are too defensive or like to buffer bara cancels to loosen them up. This level is the hardest to master, you have to use many different tactics against different players, with the only universal constants being the above mentioned concepts.
Phase 3: Hitconfirm to 236C.
This phase is the easiest of the 3 phases to actually master, but requires alot of practice as well as being very comfortable with your normals. Any hit close enough to the corner on a grounded opponent should connect to 5C 236C for your max damage bnb. Lower damage bnbs should only be used when they will kill, when landed as a part of phase 1 and your opponent is in the air or not close enough to the corner, or to generate more meter for your next 236C combo.
Notable Combos:
2A 2B 2C 5C 623B j.C dj.BC Airthrow
2A 2B 2C 3B j.BC dj.BC Airdash C Airthrow
2A 2B 5C 236C j.BC dj.BC Airdash C Airthrow (Near Corner -- remove first j.B from longer distances.)
6B 2C 5C 623B j.C dj.BC Airthrow
6B 5C 236C j.BC dj.BC Airdash C Airthrow (Near Corner -- remove first j.B from longer distances)
2B 5C 236C Dash jump C Airdash C dj.BC airthrow (This is how you connect 236C combos midscreen. The timing is difficult.)
Notes on the 2A 2B 2C 5C 623B j.C dj.BC Airthrow bread and butter.
This combo is one of the most difficult for newer and even experienced V.Sion players. There are two secrets to connecting this combo.
1) Delay the 5C slightly after 2C. Even a small delay will make your chances of connecting the combo easier.
2) Delay the jump cancel after the first j.C. This is the hardest part of the combo from my personal experience. You actually have to pause before doublejumping rather than doublejumping immediately like you would in most other character's bnbs.
The benefits to mastering this combo are its' slightly better damage and the higher meter generation, giving you more opportunities to land 236C combos or use 236A xx 236C in your blockstrings. In it's absence, you can use 2A 2B 2C 3B j.BC dj.BC Airdash C Airthrow.
Defense:
Unfortunately, this is the price you pay for your very consistent damage. V.Sion has very few good defensive options. You have to have faith in your ability to block and wait for your chance to escape.
EX Shield xx 5A 6B dash in 5B 3B j.BC dj.BC Airthrow. (This is how you set up Anti Air EX shields.)
5B Is fast enough to defeat many pokes, but has very short range.
236C can be used to defeat pokes and gaps by forcing them to block.
2A is soso against tick throw setups.
You have to learn to overcome your fear of the corner and block your way out. Any incidental damage because you were cornered is the cost of doing business -- using extreme measures to get out of the corner will just get you baited and punished. Take Calculated guesses with your blocks, heat activation, or 236C to minimize the damage you take while in the corner. More extreme random measures like j.A, jump airthrow, and 623C should only be used to defeat recognizable opponent patterns.