Sentinels of Echo City barrels along. Today's solution is the use of Feats and attribute modifiers in resolving many game situations. When you are attempting to use a trait (an umbrella term for all powers and abilities) to manipulate or affect a creature in a way that's not a direct attack (mind control, draining their attributes, teleporting them across the room), I had been resolving these as contested Feat rolls - you and the target roll a Feat, and if you are successful, your trait works.
I didn't like this, because it didn't tie into attributes at all. And, now that I have POWER as an attribute, I wanted to make sure that got some love. However, I was running into two problems: POWER can out-scale Feats a bit, and that can create some balance issues; the bigger problem was that contested rolls, while sometimes necessary, aren't really in the spirit of B/X. All magic that controls/manipulates allows a saving throw, but doesn't require a roll on behalf of the caster. You don't roll to affect targets with your fireball; you roll for damage, and the target rolls a saving throw (Feat in SSR parlance) to resist.
I've found a hybrid I'm happy with. When you attempt to control a target's mind, the target rolls a Feat (target 20), but this target is adjusted by your CHA modifier. If you have really low CHA (say 5, a -1 modifier), the Feat is against target 19. If you have high CHA (say 15, a +4 modifier), the Feat is against target 24. This is clean (only one roll to resist), keeps things on the same scale, is in the spirit of B/X, maintains balance, and allows for a difference between high and low attribute scores in how effective your traits are. Sounds like a win to me.