Splitpushing Support item

I was thinking something like:

"Grants +2 stacks when a nearby ally kills a minion. +5 for siege minions. At 120 stacks, grants Unique passive: Cleave: Basic attacks damage in an area around the initial target. Subsequent attacks against minions deal increased damage in an increased area."

I don't know what the stats would be, but it's gotta be supporty stuff. Maybe make it an income item?

Just so supports can buy something to waveclear a little better, and the stacking is to make sure other lanes can't buy it.