Crimson Surge

You unleash a rushing torrent of blood magic in a Surge, overwhelming and hindering your enemies.

Crimson Wall:
You create a wall of churning blood in a 20-foot-long, 10-foot-high, and 5-foot-thick shape. The wall is difficult terrain and obscures vision (heavily obscured). When a creature enters the wall for the first time on a turn or ends its turn there, it must make a Constitution saving throw. On a failed save, it takes 4d8 necrotic damage and has disadvantage on its next attack roll or ability check. On a success, it takes half damage.

Empowered by Blood:

You can sacrifice hit points (up to 10) when casting this spell. For every 5 hit points sacrificed, increase the damage dealt by either effect by 1d8 (to a maximum of 6d8).

When you cast this spell using a spell slot of 4th level or higher, the damage dealt by either effect increases by 1d8 for each slot level above 3rd.