First il talk about the worst situation possible and that’s being trapped in the corner. Don’t be afraid to throw out a crouch mp if he isn’t at point blank range, it will stop his dash, it has more range than his c.short, it beats whatever poke he tries to throw out and if you stuff his dash you can confirm it into a combo. Teleport out if he doesn’t have super and is point blank you will eat a far fierce but its worth it if you have the health.
Necro also has the option of using jab spin punch since its safe and it gets him close to you. the best option against it is ofcourse red parry and punish but its also the hardest so if you block it you have to guess after that. If you think he is going to stay grounded the best thing to do is reversal kara grab since it stops every hit he tries to do after that. Worst case scenario is you do kara grab he does instant drill kick and he is in your face. He can also back dash to avoid the throw but he can’t punish you because you have already recovered.
If you use resets make sure you are always at advantage since his point blank target combo is fast and leads to super. A very good mix up against necro is hit>lk.tatsu>stand lp>rh tatsu dash in forward jump and dive kick. If he tries to get up fast you can hold right or left and you will go on the side you chose while he is still getting up and you have perfect timing for a meaty stand mk into super or whatever. If he doesn’t get up fast you still have time to chose what to do.
Necro is low tier for a reason meaning that its hard for him to get a good offense going if you are careful and don’t make mistakes. His jump is also floaty and he is slow overall making it easier for you to set the pace of the match and react to his jumps. He will try to bait you most of the time by using empty jumps, delaying hits etc. So look out for that and you can get your style against him started. Using air hadou and spacing is a must for this match up since making one mistake against a necro with super means you are dead most of the time.
Parry the second hit of drill kicks with down parry always!! That goes for your wake up game in the corner too because the second hit of meaty drill kick can’t be parried with forward. If its a meaty drill kick on your wake up it can’t be punished even if you parry so just use throw.
You can punish drill kicks with a full combo depending from how high in the air your opponent does them. If its instant (the first possible frame) a good option is to parry the first hit and rh tatsu into what ever combo. If its a bit higher than that you can full combo punish after u parry the second hit but the timing is very strict. Another option is to use stand fierce after you parry the first hit, what happens is you either trade or if you are fast enough you beat it clean.
Edit:
Blocked electric snake can’t be punished only if necro does it outside your c.mk range other wise its punishable and its easy. You can do c.mk into combo or super or if you are not so confident you just do clean super. The punish doesn’t even need reversal timing.
Edit2: Most of the stuff in this thread won’t help you unless your are the master of online timing.
Also if you need to know anything specific just ask since I can’t recall everything I know from the top of my head.