Brainstorm about giving credit to Supports and other valuable players
"Shared" Kills
The concept is easy, Assists are designed for this very factor and are the tool to give income to whoever contributed to the takedown. I believe that this feature should be also graphically applied to the kill banners.
The visuals of the Shared Kill should display the killer, the highest damage dealt and who hard (soft too?) CCed the slew enemy with different portraits bords colors in order to easily differentiate that, to this we can add that the thing will last a bit in a corner of the screen with the addition of a small mouseover text telling us who did what.
Size and placements of said portraits is all up to who knows better than me how o program things and which is most visually efficent.