Ice Beam (Hydreigon) ~ Ice Beam (Hydreigon)
If Hydreigon is KO'd, and your remaining HP <= 23, then use Recover.
[KO Sub] If Hydreigon is KO'd, then use Ice Beam (Dragonite).
If Hydreigon has Protection, and Dragonite is to use a paralysis-inflicting move targeting you, then use Protect (self)...