Also, I don't know anything about PAD Z. Any blue healer stuff I should know about?
Avalon Drake is worth a special mention here for being an especially exceptional special-god tier monster from PADZ. He is one of the premier, top-tier subs for Athena. His skillup monster is the Sacred Green Mask.
For Dragon teams, Illusory Dragon Anima is a decent lead, BUT he can also be a sub for a Ronia team. Also for Dragon teams, Dragon Shogun is notable for his x2 Dragon Enhance active, at max skill level it is only 7 turn CD, plus he gets both a TPA and a Dark row. In fact, Dragon Shogun is superior to Draggie in almost every way - except for the fact Draggie is non-REM and farmable. Well, Shogun's enhance changes Hearts to Poison though. Hellfire Dragon Inferno is
very good for Gaia, but that's about it. Finally, Curse Dragon has an HP conditional x3.5 ATK boost for Dragon types, his AS is 35% damage taken reduction plus Dark orb enhance; he's decent as well.
Prometheus is neat as a sub because his active changes two colors to Fire.
Apparently there's a blue healer that boosts Water damage by 1.5x for a turn + 3000 HP healed, in addition to having a blue row/two-prong/skill boost.
Gaeble Chimera is a Blue Healer; his skill Ell-Heal is skilled up by Gale Wolf Hatii.
His LS is 1.5/1.5/1.5 to Healer types the same way Prometheus is 1.5/1.5/1.5 to Devil