Comments/feedback requested on homebrew magic weapon

Blood Reaper:

Requires Attunement: yes

This magic halberd gets +1 to attack and damage rolls.  Whenever this weapon strikes a creature of any type other than undead, construct, plant, or elemental, it deals an additional 1d8 necrotic damage as the weapon drains their blood.  If it scores a critical hit, it deals an additional 7 necrotic damage.  If a creature is reduced to 0 hp by this damage, the wielder gains 2d6 temporary HP.

Curse: Once attuned to this weapon, the wielder cannot voluntarily relinquish it or make weapon attacks with other weapons unless Remove Curse is cast on them.  If the wielder goes for 24 hours without using Blood Reaper to make a weapon attack against a creature of a type that the weapon deals additional necrotic damage to of CR 1/2 or greater, they become more aggressive and irritable and must make a DC 10 wisdom saving throw any time they're in an emotional situation or try to attack someone.  If they go for 48 hours without striking a valid creature with Blood Reaper, they lose one hit die as Blood Reaper drains some of their blood.  Both penalties end once the wielder uses Blood Reaper to kill a living non-plant creature of CR 1/2 or greater.