The weapon
The Jötunn Star, often written Jotunn Star, is the wonder weapon of Totenreich: a Norse artifact that the people of Eidskallen hid from Group 935, a lantern of blue fire forged within a skull and swung on a barbed iron chain. The game describes it as a lantern that “casts death-dealing fireballs”. It costs 950 Essence from the Mystery Box, and it is free through the quest below.

Jotunn Star
A melee wonder weapon with wide sweeps. Five hits in a row unleash a stronger blow that releases spectral energy. It stores the essence of the enemies it kills, which keeps its wielder warm and feeds its two special attacks.
Flame Strike
Once the Star is charged enough, it fires an explosive fireball that sets the enemies on fire. The main quest uses it again and again.
Flame Tendril
When two players or more hold a fully charged Star close to each other, a fiery cord links them and drains the life of anything that crosses it.
An upgraded Flammenfalle Trap strengthens the Star, and the three traps of the final boss fight charge it. The Star is needed for the main quest.
