u/CollectionNo7513

Hello! I am a first time dm and making a homebrewed artifact for my players, and just generally would love some advice on if this is good or can be tweaked. They get it when they clear a trapped tomb/dungeon of a dead blood witch and I'm not sure if its overpowered or completely useless haha

Circlet of the Blood Mother:

2x per day, user can use a bonus action to take 1d4 damage (per spell level) to enhance next spell. The circlet doubles the damage or effect duration of a spell.

The user then must roll a Constitution saving throw of 10 + spell level. If they fail, their max hit points are reduced by the damage they took until next (long/short?) rest.