most of the changes in MYMU are teemoing mages
FYI Teemoing a champion means adding unnecessary/useless mechanic into champion's kit then nerfing the champion's actual power, causing the champion to become significantly weaker because the new mechanic does not compensate the loss oftheir original power. (for example rito added moving while stealth in bush and bouncing shroom in teemo's kit which are now globally considered as useless mechanic, then heavily nerfed his ap ratio, cd and duration of his shroom, causing direct nerf to teemo's power).
some mages we can consider teemoed: Viktor(a burst mage) gets DPS on ult while his maind dmg ability deathray and augment were nerfed to become unreliable.
Fiddlestick gets more mobility but majority of his kit require him stand still.
vlad gets a reworked kit which has tones of counterplay to the point where there are few counterplay to his counterplay.
veigar gets ap when dmging enemy champ but lost the ability to oneshot people and still have to farm q, the play stlye is barely changed at all.
many of the other mages I have not faced or played, but from the patch note it looks like majority of them got number nerfed(both in their kit and items) just for some unnecessary mechanics...
and no one bats an eye. Make a mage ureliable, everyone loses their minds.