As chaos ensues, all Kellon can see is the massive threat rising on the other side of the room. Such a monstrosity would surely crush any caught within its reach. Yes, destroying the artifacts was important, but so was not having everyone die down here. Kellon grasps at his holy symbol and points at the mound. "Heartseeker!"
Spoiler: OOC
Show
Kellon casts Guiding Bolt at the mound.
Spell Attack: (1d20+5)[21]
Damage: (4d6)[17] Radiant
If it hits, the next attack roll against it gains Advantage.