Overall Rating: Orange. This means that
investiture of flame is an OK spell.
Overall Notes: Damage immunities and resistances are fine but the passive effect has terrible range and the AoE effect is mediocre damage. The biggest issue here is that, if you are using the fire immunity it’s very likely that your enemies are immune to fire damage. Also, requires concentration so you can cast the spell, and lose it before you’re able to use the AoE feature.