Twin Bolts of Demonfire

You summon two churning bolts of dark-colored liquid fire from the lower planes and hurl them at targets within range. You can hurl them at one target or two.

Make a ranged spell attack for each bolt, with advantage on your attack roll if the target is a fiend or undead. On a hit, the target takes 3d6 fire damage and 3d6 necrotic damage, or 3d10 fire damage and 3d10 necrotic damage if the target is a fiend or undead.

The target must succeed on a Constitution saving throw or its hit point maximum is reduced by an amount equal to the damage taken. This reduction lasts until the target finishes a long rest. The target dies if this effect reduces its hit point maximum to 0.