Basic Overview -----
One of Zas's strengths is limiting movement. He can keep the opponent still with his fast horizontals, pull in moves, pokes with good coverage, and very powerful ring out game (especially reverse ring outs).
Once the opponent is conditioned to slow down and wait, Zas can enforce grabs, low pokes, CH fishing tools, and moving around on his terms to really get into the opponent's head.
Curses make Zas go from great to pretty damn bonkers. You can put up to 3 curses on an opponent, and all of them get used up at once when you use a move that can freeze time. Curses are mainly obtained by landing moves that combo into 6K (usually from CH fishing, catching movement, and block/whiff punishment). They don't carry over between rounds.
Stacking 2 curses on an opponent gives him access to a powerful low in 1BB, stronger normal hit whiff punishment in 4AB and 66A+BB, extra combo damage with 46BB extensions and a even stronger ring out game with 1BB, 4AB and SAB into follow ups.
Some of Zas's weaknesses are his lack ranged block punishment at i12/i14, and his damage isn't massive outside of curse combos & certain LHs.
Standing Block Punishment -----
i12: 6K°, AA, KK, 2A. i14: b:K. i16: 46B, 3AB, 66K, SA. i18: 8B+K. i20: 6BK, 3B, 44A+B i22: 6B+KA, 66A+BB
Crouching Block Punishment -----
i12: 6K°, wrKB. i14: FC 3K. i16: 46B, SA. i18: 8B+K. i20: 6BK, 44A+B. i22: 6B+KA, 66A+BB.
°Using 6K to apply a curse is sometimes more worth it than your other block punishment up until i18. At i20, use 6BK - 6K to apply a curse.
Whiff Punishment -----
6B+KA, 6BK, 22B, 66A+BB, 44A+B, 46BB, FC 3K, 4K LH °
°The condition for 4K's LH is when you use it as a whiff punish or CH vs a 'heavy' attack (any move that would be level 1 on GI).
Reading Movement -----
3AB, 3AK, 66A, 6AA, 6AB, iFC 3K, 4A.
Tools Against Standing Guard -----
Grabs/side grabs, 11B, 214B+K, B+KK, B+KG, 1B, 2B+K, 1A. SC 1AB, SC grabs, 1BB TS2/3 Detailed conditioning-adapt-abare
Curse Applying Tools -----
6K, 3K, A+BK, B+KK, RE K, 6A+GK, SC 2A+B, SC B+KB, CE.
Plus these moves that combo into 6K:
CH 6AB, 66A, 6BK, FC 3K, 6B+KA, 214B+K and any launch combo enders. Details applying-curses
Curse Spend Options -----
1BB, 46BB, 4AB, 66A+BB, RE BB, SAB. Details spending-curses
Post GI options -----
level 1: +8. Frame advantage level 2: +16. 46B/66K vs no reGI, wait and punish vs reGI/RE. Level3: +28. 6B+KA/44A+B/66B+K LH vs no reGI, 2A+B/wait and punish vs reGI/RE.
Guard Damage Game -----
4A - 10%, 22A - 10%, 6BB - 11%, 66B - 9%, 44(B) - 15%, 4B+K - 15%
6BB, 3AK, 9B, 44[B], RE B burst giving 44[B] LH combo.
Ring Out Options -----
Front: 46B, launch - b:K - 46:B Left: launch - K6 Right: 22KK, BT B+K, 4B:B BT A RRO: CH 3AB, CH 4B:B, wrB, 44A+B, CH 4B+K, 6A+GB, 4A+G.
Details ring-out
Neutral Pokes and Tools -----
Close: AA, A6, 2A, 1A, B, BB, 2B, 1B, 4B, 3K, 22K, wrK, FC 3K, 2B+K, Grabs.
Range1+: 6AA, 6AB, 3AB, 3A(B), 3AK, 4A, 66A, 22A, 44A, 6BB, 6BK, 66B, 44B, 6B+K, 4B+K, 22B+K 214B+K.
Detailed range-and-neutral
RE Safe Moves -----
you can step after these no matter what character you face.
AA, 6AA, 66kB, FC 3K, 22K.
With A6, 3AK, B, 6B+K, 2B+K you can step most REs however ones you cant you can SC or RI out of.
Okizeme Options -----
All grounded hit: 1A, 1K, 22A, SC A+B
Right Roll: 3A(B) 2nd hit, 2B, 66A+B
Left Roll: 3B, 44A+B, 22B, 46:B
All also if feet towards: 46:B, 1B, 22B, 11B, 8B+K.
These options are consistent if the opponent is already on the ground. Other tools like 6BB and 66B are likely to hit rolling opponents in certain oki situations, such as after ending a combo with BT B+K.
Meter Usage-----
Zas's Critical Edge creates a dilemma for his opponents. Any attack against Zas could be risky when he has meter because of the auto-GI on his CE. Because of this, you can catch a lot of opponents trying to sidestep it, or they might be hesitant to do anything. Use this mind game to your advantage.
The auto-GI on CE begins at frame 8. With no curses, Zas's CE will auto-GI all mids and lows (except break attacks and unblockables), deal 75 damage on hit, grant +8 frame advantage on block, and will apply a curse to the opponent on hit or block. This version of CE can be used even if the opponent is cursed by using 6A+B+K.
With 1 or 2 curses, CE will begin to auto-GI all attacks (except break attacks and unblockables), including highs and throws. You will lose your curses if CE whiffs, and you'll be left with 1 curse on hit or block.
With 3 curses, CE's aGI becomes an RI, meaning any attack in the game will be deflected. You still lose all of your curses on whiff, and you'll still be left with 1 curse on hit or block.
His Soul Charge is more mix up based with moves like SC 1AB and his command throws (SC 214A+G or SC 236A+G). He also gains access to a faster and ranged B+KK in the form of SC B+KB.
His Soul Attack is pretty standard. It is best used after a launch combo (such as 3B - b:K) into oki pressure. SAB can be used to stop time, but it is recommended only for specific ring out angles as an i16 block/whiff punish.