These heroes may be not that imba in the pro game but in the pub game that almost always consist of 3-6 players that dont know to counter the heroes and just play for fun. these list of heroes will shine brightly in this type of game.

STR
Axe ,Bristleback ,Legion commander ,Primal Beast


INT
Death Prophet ,Leshrac ,Lion ,Queen of Pain ,Silencer ,Muerta ,Storm Spirit

AGI
Blood seeker ,Ember spirit ,Slark ,Sniper ,Urza ,Spectre

UNI
Dark willow ,Sandking ,Pangolier ,Timbersaw ,Void spirit ,Techies ,Wind ranger


the most imba in all tier game is "Meepo" but it's not easy for the new player

the evidence that this hero is so strong is he is one of the most play hero for the high ranker and high win rate player. you can see it yourself if you visit them in the game.