A Supernal's strength relies on mana, but it's not the only way to grow stronger.
Other than increasing their rank, from Awakened Supernal to Aspirant Supernal and so on, a Supernal could also grow stronger by increasing the number of imprints they can access. And to do that, a Supernal would need to please their Patron God.
Kai needed to complete quests to please the Goddess of the Primordial Night.
Protecting and comforting others is how Bree pleases the Goddess of Childbirth.
Please the Patron God enough, and they might grant a Supernal more of their power through giving access to more Legacy Imprints. Climbing the rank path is harder for Angels as they're prohibited from using mana ores.
For Angels to progress to the next rank, they would need to make use of null crystals.
A far weaker source of mana.
Not only is it weaker, but null crystals are hard to obtain, and they carry side effects.
