The caster is fixed in place for two actions as they open a miniscule portal to a faraway dead star, channelling an infinitesimal fraction of its killing light towards a single target. During casting, the caster is immobilised casting and has disadvantage on saving throws. If the caster takes damage while casting the spell fails and the spell slot is used. Once the portal opens on the second action, make an attack roll against a single target within range. A single lance of invisible light leaps forwards, igniting the air as it passes. On a successful hit the target takes 7d10 radiant damage and 6d10 fire damage, and must roll a constitution saving throw. On a successful save, it takes 4d6 necrotic damage. On a failure, it suffers 8d6 necrotic damage and is poisoned for one minute. While poisoned in this way the target takes 2d6 necrotic damage at the start of each round.

If cast with a spell slot of higher level than 6th, the radiant and fire damage both increase by 1d10, the initial necrotic damage on failed save increases by 2d6, and the lingering necrotic damage increases by 1d6.