Channeled Pyroburst

A sphere of fiery energy comes into being before you. You channel energy into it, causing it to bubble and seethe with power. When you have poured enough energy into the sphere, you send it flying into your foes. This spell creates a bolt of fiery energy that blasts your enemies. The spell's strength depends on the amount of time you spend channeling energy into it. If you cast this spell as a swift action, it deals 1d4 points of fire damage per two caster levels (maximum 10d4) against a single target of your choice. If you cast this spell as a standard action, it deals 1d6 points of fire damage per caster level (maximum 10d6) to all creatures in a 10-foot-radius spread. If you cast this spell as a full-round action, it deals 1d8 points of fire damage per caster level (maximum 10d8) to all creatures in a 15-foot-radius spread. If you spend 2 rounds casting this spell, it deals 1d10 points of fire damage per caster level (maximum 10d10) to all creatures in a 20-foot-radius spread. You do not need to declare ahead of time how long you want to spend casting the spell. When you begin casting this spell, you decide that you are finished casting after the appropriate time has passed.