User blog comment:KaiserLos24/Sion Rework Idea/@comment-8506165-20140217134537

Too strong at the moment just because of that W. All damage from all sources gets reflected? Screw attacking things, just stand around with R on farming minions and watch the bruisers basically hit themselves in the face, the DPS mage whittle themselves down to nothing and come late game, just buy a Thornmail and watch the ADC eat themselves for breakfast.

Okay, maybe I'm exaggerating a bit, but Sion's effective health is ludicrously high when you factor in his high lifesteal from ult, passive health from killing enemies and resistances (which he should build unless you're going for the hilariously unviable melee carry Sion) and now 10% reduced damage taken thanks to his passive, so 12% of that as magic damage to any squishy that's trying to kill him is going to be a massive chunk of their health. False choice - attack Sion and die faster, or don't attack Sion and let him kill your team anyway? Bad. There's a reason has flat damage rather than % damage received on it, and only applies to autoattacks. That's on an ability that costs mana and has a downtime, rather than on a passive - granted, Rammus also gets resists from DBC, but you should be able to see my point here, I hope.