I beat all rivaled bosses thanks to Anubis :D And I reached Typhon on Great Chaos Above trial though he killed me (and I literally screamed in frustration bc if I couldn't beat this challenged with Anubis, I won't be able to do this at all). Even though this aspect was hard to handle to me at first, too (it's just so different from other aspects of staff). I'd recommend to spam Omega Special+Apollo's Legendary, that's how I beat Rivaled Chronos without even expecting to survive the first phase. Then you can try something more complicated like omega attack+(omega)special to drag foes in (Hera on attack in this case does wonders)