Physical attackers (single-target)
Move Hariyama to viable
I think Hariyama is a viable attakcer, it has nice abilities, good coverage and has good bulk. Even though it's DUU I think it's good enough to be in the viable section.
Move Arcanine to niche
It is pretty harsh to put it in unviable, I think Arcanine brings some viability, even though it's still not really good.
Move Heracross to unviable
why would you use this pokemon
Move Mega-Beedrill to unviable
This is one of the worst megas, incredibly predictable, and even though it it has good speed and attack, it gets beaten by so much I don't even think it should be a niche pokemon when you have other strong attackers
Physical Attackers (spread)
Move Mega-Aerodactyl to viable
Mega-Aero has got a lot of interest lately and I think that's deserved. Rock Slide is pretty useful and mega-aero has amazing speed + good attack so I think it's pretty viable :]
Special Attackers (single-target only)
Move Salamence to niche
I don't really think Salamence is a viable Special Attacker, even though it has nice coverage i think it's not really amazing
Move Mega-Sceptile to niche
This is a pretty bad mega, its a fast mon but yknow its pretty bad
Special Attackers (spread)
Move Volcarona to viable
Heat Wave Volcarona is pretty viable, volc is a viable mon
Move Mega-Camerupt to viable
Mega-Camerupt is an amazing pokemon in duu and I feel like it has viability in DOU especially under trick room n_n
Mixed Attackers
Put Hoopa-Unbound in viable
I think we saw this is a quite viable pokemon
Substitute Attackers
Move Mega-Garchomp to niche
regular garchomp is even better
Scarf Users
Move Rotom-Wash to viable
scarf rotom-wash is the best set at the moment in my opinion, it's a really strong pivot n_n