God's Trascendentals are the origin of spells

■ When a god's transcendental becomes divine magic for humans, it's usually weaker than the original. It's a problem when birth attributes and divine affinity put limits on maximum power. Even if your maximum power is strong, you have to lower the power so you don't consume too much vigor.

■ Each god has many transcendentals, but only two can be used for divine magic. Unique transcendentals can't be copied by other gods or suras, so those are impossible for humans to understand and use, therefore they are excluded. And among general transcendentals, they shouldn't be those that are too common; they could be duplicates of the divine magic of other gods, and you can't use something another god is using.
* There are now only 11 gods who influence magic, but there were a lot more in the past, and so there were often overlapping magic spells. This doesn't mean that there were also a lot of attributes; birth attributes were the same as they are now, but there were many gods who had the same attributes. For example, there were many gods with fire attributes, so there was a lot of fire-attribute magic. Agni was the strongest among them, so his magic remains.

S1 Episode 34 Afterword