Hellish Sacrificial Dagger

Gain +1 bonus to attack and damage rolls.
If used to kill a creature, it automatically dies. Creatures slain may not be brought back to life
except by resurrection or wish magic. If killed creature
had an intelligence score of at least 6, gain the benefits of an Aid spell for 1 hour.
1d8 extra damage against Celestials.
Good-aligned creatures suffer 1d8 necrotic
damage from holding the dagger at the start of
their turn.