User blog comment:Shinen-san/Shard, the Broken Reflection (anti-magic support champion concept)/@comment-4636093-20150520003728/@comment-4996845-20150520163044

Yep, that's only when hit by champions. I could make it so that minion aggro would cause stack generation but reduce the heal per stack - but that would make a clutch heal with the active much less likely to happen.