Queensblade: Dreadfang

+3 Longsword, 1d8 Slashing + 1d10 Necrotic, versatile (1d10)
{b} When any number of Axial creatures you control die except via self-destruction, you may use your reaction to gain temporary hit points equal to their combined CR. This weapon vanishes on death and reforms with you in your Throne World if you possess one.
A shard of that dark light you grasped so long ago, brought at last to fruition. All hail Francesca, the invincible Taken Queen.