For the April update this month, the interaction between certain champs who can negate degeneration and direct damage effects of their opponents was largely fixed. Nodes like special delivery and rising sun now work correctly, but there are still a few interactions that I’m unsure about.
The first, is with mojo. When omega’s dex buff is removed while mojo has his anti life field up, two things can happen. If he strikes with a medium tentacle attack, he negates the following degen damage, fantastic. However if he strikes with a heavy attack hit (which is still a tentacle attack), he does not, as you can see:


Additionally, there’s the degen with dormammu that he seemingly cannot bypass with any of his tentacle attacks. You dex, and then strike with a tentacle attack that ignores passive degen and direct damage effects for the next 0.2 seconds. The expiring dex buff lasts 0.2 seconds, therefore upon its expiry, the degen applies, and then tentacle attack should cover that damage. However it doesn’t. Not with a medium, not with a heavy. As you can see: