Don't really have an answer for this one, as his only real fight started in melee. So all I can say for sure is that he would use some form of offensive magic, but just to get thing moving lets say he uses his fire magic like he did against natsu.
So August is a bit faster and hits a bit harder, but Orochi is a much more skilled melee fighter, according to Calaca. Orochi also out ranges August and has massive aoe to boot iirc. I'll wait, but I'm leaning towards Orochi right now.
Bloodlusted base August ........ he doesn’t really do anything in canon tbh so I guess he just uses sleep manip? At least with Dark August he does something, base only has a feat of getting blitzed or going Dark Form.
Status resistance seems to be pretty universal among stronger OPM characters, at least in terms of sleep and poison. Nyan was uneffected by sleeping gas. Metal Bat resisted it but smacked his head to shake off the effects. Poison has never worked on anyone aside from a half dead and exhaused Garou, and he still was resisting it.
Which means this is likely a complete stomp now considering he will never be able to kill/hurt Orochi (Type 2 and 3. High-Mid Regen), while Orochi can nearly 1-shot him. Speed dosen't matter at all either.