Different Types Of Kills.
If Player A is killed by Player B, When player A respawns if the first thing player A does is kill player B When Player B explodes red text will pop out (Like Nexus) Saying "REVENGE!" And will reward player A with a bonus point for that kill.
Assist Kills: Simply if too or more players kill one person. Then its an assist kill. Same text flys out only it says "ASSIST!" No points awarded unless its a team match. Then 1 point for each.
Combos:
Dosen't Effect much. This sums up what the text would say.
1 kill = GOOD SHOT!
2 kills = DOUBLE KILL!
3 kills = TRIPLE KILL!
4 kills = MULTI KILL!
5 kills = AWESOME!
6 kills = AMAZING!
7 kills = INCREDIBLE!
8 kills = COMBO X8
9 kills = COMBO X9
10 kills = COMBO X10
And so on until it hits something like x99 that no one will ever get in a single kill streak XD.
But yeah, I think this will be good to try and make the player try as hard as he/she can to get as high a combo as possible.