In looking at and playing with Divine Flare in the Sigils of Hope skill tree, the ability seems to have a mechanical flaw that could be improved. Currently, the ability requires you to cast a Sigil, costing 35 mana base, then cast it again to detonate the Sigil at another 35 mana cost. The damage done by sigil is not commensurate with its cost–70 mana and 2 cast animations.
Perhaps having the detonation cast also summon a replacement sigil would smooth out the feel of the ability and bring it in line with other spells/abilities for damage output.