Corruption was fucking horrible. Twilight Devastation, however, was great seeing it wipe off mobs. But it's still a horrible system when you see a total RNG of getting, going through a total RNG of procs, to see it do 30-60% overall dmg. It just incredibly stupid. I personally enjoyed TW and reaping flames, but it was still a stupid thing, but satisfying visually. Also, there should have been a vendor for it right from the beginning and not 1.5 years later, but even then Blizzard managed to fuck it up by giving it on a rotation period which, yet again, made zero sense. Having essences was/is also very retarded, just like the pointless leveling of the neck because grinding was required throughout the expansion. BFA made it impossible to have an alt and Shadowlands seems total opposite of it luckily.