ver.

Searing Seal

Enchantment
Fire
Level 4
Charges: 6
Gain Seal of Searing.
Whenever a unit takes fire damage, the seal gains that many charges.
When the seal expires, it deals 1 fire damage to all enemies in line of sight for every 5 charges it has.
The seal lasts 6 turns.
Recasting the spell will expire the current seal and create a new one.

Attributes:

6Duration

Upgrades:

4 - Slow Burn
On expiring and dealing damage, gain a buff that redeals half the damage, then, finally, one that deals a third of it.
4 - Chaos Seal
Gains charges separately from fire, lightning, and physical damage, and redeals each on expiration.
5 - Fire Harvest
For every 100 damage dealt, summon a flame spirit.
Note: May be incomplete, see limitations.