Bachra's Curse of Predation

You place a curse upon a creature you can see within 90 feet, causing a predatory stalker to form out of essence from the Lower Planes and seek its death. The stalker appears on an unoccupied space within 10ft. of the cursed target and uses the statistics of a hunter shark, with the following caveats:

• It's type is fiend as opposed to beast
• It lacks the Water Breathing trait and has a fly (hover) speed of 40 feet
• It is resistant to cold, fire, and lightning damage, as well as bludgeoning, piercing and slashing damage from nonmagiccal attacks
• It can't be charmed or frightened
• Its attacks are considered to be magical for the purposes of overcoming damage resistances
• It recovers 10 hit points at the end of each of its turns, provided that it has at least 1 hit point

Roll initiative for the stalker, which has its own turns and is not under your control. The stalker always knows the location of the cursed creature, who can't become hidden from it, and it will spend all its turns pursuing and trying to slay the cursed creature in the most efficient manner available, caring not for self-preservation if that would hinder its objective. The stalker disappears when it is reduced to 0 hit points, when the cursed creature dies, when you dismiss it (no action required) or when the curse is ended by a remove curse spell or comparable magic.

If your concentration is broken before the spell has reached its full duration, the stalker does not disappear and you lose your ability to dismiss it. Roll a d20: on an 11 or higher, the curse ends and the summoned stalker targets the nearest non-fiend it can see at the start of each of its turns for 2d4 rounds. On a 10 or lower, the curse rebounds, in which case the spell will last for the duration with you as the cursed target.

At Higher Levels. When you cast this spell using a spell slot of 5th level or higher, you may use the statistics of a giant shark instead, applying the same list of modifications. When you cast this spell using a spell slot of 7th level or higher, the summoned stalker can move through other creatures and objects as if they were difficult terrain, and the spell's duration increases to concentration, up to 1 hour.