User blog comment:Grrrbear26/Concept Battle 1/@comment-6719710-20150317235133/@comment-10958553-20150318000144

It can mean that. It can mean a lot of things.

It could mean whenever an enemy champ does X you get a whole new ability.

An ability does extra stuff if an enemy has done X in the last few seconds.

You can only use an ability if an enemy has done/is doing X.

Shaco has one of these. People who run away take extra damage.

Maokai's passive is also one of these.

It can be a lot and I MEAN A LOT of things.