Stoneborn pact on which supports?
Can I have a list of supports who would use this keystone?
Is Maoki better with it or CoTC for support?
Can I have a list of supports who would use this keystone?
Is Maoki better with it or CoTC for support?
Tends to be good with champs who are peel types/stack health/ have many slows in their kit. Braum can use it pretty well, (Q+ ult), nunu, sion, and nautilus could consider using it as well. Alistar might still prefer colossus, leona might still like colossus, thresh I think might like stoneborn due to having CC on 3 out of 4 of the spells in his kit.
Yep. I've had success on it with:

And I can see it working well for:

Phreak suggested that it might actually be viable on janna as an alternative to windspeakers, as her q/w/ult would then not only peel, but allow people to turn and heal up on the target(s).
I'm skeptical as janna doesn't have much hp, but perhaps the reliability of her cc might make it a quantity>quality thing for healing. Might be worth trying.
I've had some success as mundo support with it. You need to be pretty reliably landing cleavers though since he doesn't do much else support-y, although he can somewhat viably bodyblock.