Aldous' mark

The rock gnome wizard Aldous created this spell. The caster creates a powerful rune of protection that empowers his allies' will to survive and face challenges that would have likely been insurmountable. The rune affects a radius of 20ft on any surface the caster can touch.

For allies within the circle, they receive an initial 2d4 of temp HP for the round they are within the runic circle. This temp HP given to allies increases by 2 for every enemy that is also within the runic circle. When it is once again the caster's turn, they may choose to hold concentration on the spell, preserving the temp HP gained by allies. The runic circle disappears, but as long as the caster holds concentration, and at least one ally still has remaining temp HP, the caster may revitalize the runic circle as a bonus action and recalculate temp HP buffs for allies within the newly revitalized runic circle. If the concentration is not held or the duration ends, the spell ends and all temp HP gained is lost.

If an ally leaves the circle, they may keep any temporary HP gained during their time in the circle until the spell ends.

At Higher Levels. For every level above 2nd, an additional 1d4 is added to the initial temp HP given when the spell is cast.