Forward Throw, that double jump leads to an unblockable cross up so thunder knuckle is her only option for that, but you can benefit from Jump HK if so your trade is more worth it. or elbow to bait it., however forward dash twice and walka bit will beat the thunder knuckle… unless maybe she delays it might beat it out, fwd dash x2 and jump will be a safe jump for you.
Back throw- I hardly get to fight Vipers only one being Manny and that was only once. But back throw I’m not sure what is viable for her as I know the crossup method can be beaten by a thunder knuckle unless some finds something to use thats either a safe jump or ambigious. (don’t feel like going into the lab to find anything)
After a sweep if she has meter, you can OS ultra 1 on her if she does EX seismo…Vipers normally won’t burn two bars if they have 3-4 meters since Seismo is safe, and completely invincible for a good while.
If viper as the life lead do NOT approach her. Her thunder knuckle will at worst trade with whatever you do, Seimso is the only thing you’ll worry about then, in which case EX run can be your friend there to close space since it does not break armor… same with Focus Dash, once you close spaces its footsies and being wary of Seimsois/fakes, Super jumps and thunderknuckles. remember Burn Kick can be beaten by MK tatsu, Cr. lk?, cr mk. TK izuna and EX bushin flip*.Not sure if a cr mp is any use there i never bother to try it since there are better options.
**This will just cause you to avoid it, though you may mindfuck the player and catch them off guard I would use this sparingly or via armour cancel.