Does this work with your private plugin aswell?^^ 

(Examples: That it only attacks the other team (like the heli), only counts kills within an event round)

It's safe to assume that most public plugins will not work with private ones.

Zonemanager, Spawns database and  Kits do work with the Arena plugin.

I don't see any references to "Arena" in those plugins; they work with Event Manager though.

It has no awareness of events coded in.  That would be non-trivial to code (tracking what entity is on what team to know if they should count for the streak).  That would add overhead to the code, that most operators would not require.  I will pass on coding it, but the mod author might add it as they could probably come with an elegant solution that I am not advanced enough to think of.  If you find a bug, I will help fix it though. :)

Oke thanks!