[Professor_Dyar]

I can't answer your last question, however:

1. the angels of MA Pythium represent the Eastern Orthodox-inspired religion of the Byzantine-derived nation. LA Pythium has been taken over by the Serpent Cult, and it is to be presumed that the deity and corresponding divine servants that protected MA Pythium have left as well. So no, LA Pythium cannot summon angels. They can summon the Daughter of Typhon instead.

2. Are you referring to hydra commanders (e.g. the Daughter of Typhon named Hydra), or are you referring to recruitable hydras? Non-commander units have item slots, but you cannot see them and cannot use them unless you make them into commanders somehow (e.g. Gift of Reason).