Adaptive Helm needs to be looked at.
I got stupid pissed about Adaptive and did some looking into it. Just Raw numbers nothing else.
If a target with adaptive has 200 MR goes against Void, Morello's, and Sorc with no other form of Pen.
200 - 80 (void) = 120.
120 (remaining MR) - 33 (Morello and Void). = 97 MR.
97 MR = 49% damage reduction.
Saying that you take 1000 RAW damage from a secondary Ryze E Q.
It is cut to 510. Then adaptive takes over. 510*.8= 408 post mr and adaptive.
408 = 59.2% damage reduction. OR in MR terms.
149 MR.
The lower the Base MR, the more effective Adaptive becomes.
This isn't just for Ryze.
Its for

I left out a few other champions that it would affect.
This isn't accounting for AD champions that do use multiple spells either.
Even the AD equivalent is only 12% reduction.
While
is 20%.
At least make them the same. Either make Tabi 20% or make Adaptive 12%.