I dont have a setup so i cant find the exact %'s but when you grab sheik you want to dthrow her at 0%. Then there is a % range where upthrow will give you followups(preferably upairs). At higher %s where upthrow wont get followups your dthrow will give you followups. At high % i usually dthrow nair her off and edgeguard but if shes high enough or you think shes going to DI up you can dair/upair. If you guys could find the % ranges thatd be great.
Moreover, when sheik dthrows you at around 20-30%(it could be other %s too im not really sure) you can escape. Im not sure where the DI for this is but i think i usually DI away. You should be able to jump out but this is generally a disadvantageous position. Instead, spam A as you get close to the floor. What happens here is an aerial interrupt, which is when your nair animation starts but you land within the autocancel windows putting you into normal landing lag(4 frames). At this point you should be buffering spot dodge. Pretty sure shiek can land a dash attack but i dont think that will give her any guaranteed followups. If you know shes going to wait for you to spot dodge start using mixups like buffer roll. When i get 20XX ill look more into it but I doubt sheik can actually get a guaranteed grab even if shes frame perfect. I got the whole idea from playing mewtwo and using DJC aerial interrupts instead of wavelands.
Also people need to CC against sheik more here's some data i posted before on the mewtwo boards, mewtwo and yink are the same weight.
Shiek's tilts are very good combo starters since they have medium base KB and low KB growth. However, this also means you can CC these moves until relatively high %s since Mewtwo is a middleweight. CC can lead into dtilt or grabs. If you get caught in your shield by tilts you can shield DI in to grab, if not your best option is to buffer roll. If you get caught, ASDI away by using the c-stick in conjunction with regular DI. Below are the max CC %s for each unstaled tilt.
Ftilt: 84%
dtilt: 108%
Uptilt: -both hits: 89%
-second hit only: 129%
CC dtilt gives you free ass followups or even a kill setup. Either way you can knock her offstage and then edgeguard her over and over again.
Speaking of which I noticed something wizzy does against sheiks. When sheiks up b onto stage wizzy reacts to the first part(the jump before the poof) by refreshing invincibility. Timing it like this makes it so that you can hold on to ledge until she reappears without the fear of being hit off. Now if sheik is low % the optimal tactic is refresh your invincibility with a bomb pull ledge regrab. Punish in whatever way you want after that. I believe someone on the yink boards said something about ledgeattack-> bombthrow -> aerial. Idk be creative.
Sheik is very easy to combo so improve your punish game instead of camping the whole match. Even if you dont 0 to death her your goal should at least be getting a combo that leaves her offstage off of that one bomb hit confirm. Edgeguarding is the most important thing in this MU.
Edit: I also posted something on that dthrow tech chasing fastfallers thread you should all check it out.