Horn of Valhalla, Iron

You can use an action to blow this horn. In response, warrior spirits from the plane of Ysgard appear within 60 feet of you. These spirits use the Berserker statistics. They return to Ysgard after 1 hour or when they drop to 0 hit points. Once you use the horn, it can't be used again until 7 days have passed.

The iron horn summons 5d4 + 5 Berserkers. To use the iron horn, you must be proficient with all martial weapons.

If you blow the horn without meeting its requirement, the summoned Berserkers attack you. If you meet the requirement, they are friendly to you and your companions and follow your commands.