Surging Healing Beam

A healing spell specifically devised to be cast by those not typically able to do so, but at the cost of stability.

Choose a creature that you can see within range to designate as the target. An unstoppable surge of positive energy beams from you in a visible line to the creature.  The beam takes the form of a cylinder with a 3 foot diameter and it emits dim light.  At the start of your next turn, the energy washes through the creature, causing it to regain hit points equal to 2d12 + your spellcasting ability modifier.

• One you begin casting, you cannot stop casting this spell early.
• If the target moves less than 20 feet during casting, your beam tracks the target so long as they stay within range.  If the target moves out of range at any point in time, they move more than 20 feet, or less than 2/3rds of the beam can reach the target after they finish moving, the spell feeds back to its caster.  The feedback effect stops the spell and immediately causes 2d12 radiant damage to you.
• If another creature is between you and your target at the start of your next turn, the target does not regain hit points.  Instead, the creature between you and your target regains hit points equal to 1d12 and you take 1d12 radiant damage.  If the creature is undead, they are not affected and you take 2d12 necrotic damage.
  
  • If multiple creatures are in-between you and your target, the creature closest to you is the one affected.
• This spell cannot target and has no effect on constructs or undead.

At Higher Levels. When you cast this spell using a spell slot of 4th level or higher, the amount of healing and damage increases by 1d10 for each slot level above 3rd.