Tamerung´s Oscilating Spears (Leviathan)

You conjure three black metal spears, that rumble with power as they rotate around you.

Your gain +1 to AC. Whenever a hostile creature moves of its own volition within five feet of you, you can use your reaction to make a spell attack with one of the spears against this creature. On a hit the spear disappears and the target take 3d10 piercing (magical) and 3d10 thunder damage. On a miss the spear stays with you.

On your turn as a bonus action you can make a spell attack against a creature you can see within 60 feet, expending one of your spears. On a hit the target takes 3d10 piercing (magical) and 3d10 thunder damage.

The spell ends when you expend your last spear or cast this spell again.

At higher levels: For every two spell levels above level 4 you conjure one additional spear and every spear deals +1d10 piercing (magical) and +1d10 thunder damage.