I think there should be event in PK arena which can be hosted by staffs, staf will set time for how long event going to last, when the time is over player with most kills will win. This will make use of the PK arena, nobody is using it unless if staff broadcast it. Sorry for bad grammar  

Just to clear this up,
A staff member will host an event that will consist of players trying to get as many PKs as possible in the set time limit.

I imagine this event would also work for Classic  

kinda like this idea
even though i already expect that event will be so lag  

this would be good since the pk arena is always empy  

Yeah, this will also help players get more kills and players which are good in pking and suck at playing events can now win  

I remember ULMS in era PC. But if this were to be in iera, there would be a load of lag.  

Hmm perhaps max number of players and larger map?

The problem is only napalms and other grenades