Actions

Multi-Attack - The Lost Spirit has multiple attacks depending on its summoner's level. Starting off, it can make one attack. When the summoner's level is 11th, it can perform two attacks when it takes the attack action, and three attacks when the summoner reaches 18th level.   Soulrend - The Lost Spirit makes a melee attack against a single target that deals damage dependent on its type. Living targets take 1d8 + Your Intelligence Modifier in Necrotic damage, and Undead, Abberations, and Mutants take 1d8 + Your Intelligence Modifier in Radiant Damage.   Become Invisible - As an action, the Lost Spirit can gain the Invisible condition.   Twilight Vesper - Once per day, the Lost Spirit can conjure a channel of its own soul energy in a 30x5 foot line, which it can relocate as a bonus action up to 60 feet away. When a target enters the spell's area for the first time on a turn or starts its turn there, it is engulfed in wisps that tear its essence apart, and it must make a Constitution saving throw. If it is Undead, an Abberation, or a Mutant, it takes 2d8 radiant damage on a failed save, or half as much damage on a successful one. If it is a living target, it takes 2d8 Necrotic damage. Targets entering it for the first time on their turn or starting their turn there have their movement halved regardless if they make a successful saving throw. The Vesper lasts for 1 minute and the Lost Spirit must concentrate on it. This damage improves to 4d8 when the summoner reaches 11th level, and 6d8 when the summoner reaches 18th level.   Manipulate the Physical - The Lost Spirit may manipulate or interact with objects weighing up to 500lbs as a free object interaction even while it is incorporeal or invisible, and then move them up to a distance of its remaining movement in a turn. If the object is less than 100lbs, then as an action it can throw it up to 40 feet, dealing 1d6 bludgeoning damage to the object and whatever it collides with for each 10 feet it traveled.

Bonus Actions

Moving Song - The Lost Spirit can relocate the Twilight Vesper it channeled up to 60 feet away from its current location at a point and orientation that it chooses as a bonus action.