Dragon Soul Magic

Is the Dragon Soul Magic tied to the number of Gems he explodes or the number of Damage he does to all enemies? One Plague cast took my “explode 12 random gems and deal 8 damage to all enemies” description and change it to “explode 3 random gems and deal 3 damage to all enemies” Is this a bug or are they both tied to magic? Number of souls gained remained at 15. Thanks in advance!

Purely the numbers of exploding gems.
Damage is fixed depending on amount of dragons on your side.

The Dragon Soul explodes [(Magic / 2) + 3] gems. It will always explode 3 gems, plus one more for every two points of magic it has.

Magic increases souls gained and explosions. Pretty sure it was both not just the one

No, you always get the same amount of souls, no matter the magic or how many dragon allies you have.
Souls = Fixed number.
Damage = Depends on allies.
Exploding Gems = Depend on magic.