PK does decently single target dmg. Of course he is an old hero so can't compare to those new heroes that are on the ridiculous side.
brute is useless for every single aspect. His armor is very high but cannot tank at all, I am comparing brute to SK not DW which is on a different level of rankings. Brute's ulti when in auto mode is the most retarded skill it will not cast unless the target has very low hp left, which means it will never cast because brute will die first.
Lightning master could have been salvaged if summoner was released but now he is just a Mage- brute.
Sniper never snipes anybody unless it is the NPC which you run into in chapter 18-19 raid.
I still use AP for fun and it is not that bad definitely not top heroes but shouldn't sit in the bottom 5 either. Same for the helicopter dude and witch doctor, art least they are useful for Outland.
VW used to be the top hero with EB. Those were the good old days before Ucool's dev team went insane and suck balls.
Same for panda, used to be the No1 tank in the lv80 era