Bloodbringer (5e Equipment)
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Weapon (halberd), legendary (requires attunement)
Morthos' weapon of choice; a halberd inscribed with runes of pain and death.
Soul Reaper. Critical hits with this weapon can be achieved at both rolls of 19 and 20.
Death Seeker. When attuned to bloodbringer, you can take opportunity attacks even if something specifically says not to.