These are a list of characters that are worth testing your cheapies / creations against. this was provided by @JaaShooUhh thanks to him you can all try and test your defenses with the chars of this pack that consists of:
Sanity-Obliterator
The End / %
EYES (doesn't work all too well)
Middle-God-Challenge
RetoDeMilenio / New Millenium Challenge (1.1)
New-God-Challenge
Rainbow_Crystal / Low-God-Challenge
NewCrystalDimension
Dawn (1.1)
Diamantes_Universales (1.1)
G-Francine (4P Mode)
Infinity Zero (1.1)
Undefined Universe (1.1)

Bonus: Defence-Checker:
according to op (baddo baaron) -
Defense-Checker by Rick is something I recommend for testing Top Madness (about Rare Akuma level) to lower god/nuke tier characters.

But unlike ISA and the rest, it only uses one attack method per palette (and technically a couple extras depending on what settings you enable), the details for which you can see by translating the readme. It's good for tinkering with the nitty gritty and spending time with a particular attack method instead of jumping from one to another. https://u6.getuploader.com/falljohn/download/56