So, I'ce thought of this change for Garen's W that can make its Active a bit more interesting

How about this:

Active: Damage Reduction changed to 15/19/23/27/31% from 30 at all ranks. At the end of the duration, Garen unleashes a war scream, reducing all surrounding enemies' resistances by 50/75/100/125/150% of his current bonus resistances from the passive (which means a maximum of 15/22.5/30/37.5/45).

Thoughts?