S Tier: Strongest heroes, really good against a lot of matchups, near to have a hard counterplay. Y’Bneth, Kriknak and Elsu are quite above that rank.

A Tier: Still strong out there, if well played they can excel in many games (Note: Valhein is just there if played with that off-tank Korean build. If not, tier drops are dramatical).
B Tier: Decent picks, they can be perfectly viable in most situations, still meta but not that strong as all those above.
C Tier: More like situational heroes, mostly because of their lack of mobility (except Nakroth) or a place in the meta.
D Tier: PLAY-DO-NOT, purely trash and can’t do nothing but annoy both teammates and allies. Omega can kill turrets, yes, but Kil’Groth, Rourke and Omen can do the exact same and actually provide something to the game. Toro is just a rock out there that nobody cares about and doesn’t give you reasons to attack him.