akmal it depends on how much damage they are doing. If darkdeaver could show us how much damage he was doing then yeah it's simple to get that much exp. He's got a fire pure burster lvl 82rb. At that lvl you have 551 points to put on your stats. If it's a killer then 4 points go on agi and maybe that killer might still have 42 wis but then that leaves you with 505 points on atk plus the stat bonus of rb as a killer along with the equips and the cape and quite possibly maybe a high lvl burstable saddle pet that might be using a bash saddle when his mains are not using it. Or if darkdeaver is really rich or he can buy IM points then he might even have a bash saddle on the pure burster.
So if you have a pure fire burster rb as a killer with 505 stat points on str your attack would be greater than 1.5k then you add equips you can do some godly damage XD