This seems like a good thread for this:
One of my players recently defeated a sub-boss and acquired a weapon i described as a "Black Axe"
Said Black Axe is filled with the essence of a great old spirit of the night itself, which has immense power, and itty bitty living space. it's not evil, but OH GOD do first impressions not tip you off to this. Basically, an Ancient King defeated the Night and bound it's essence to the Weapon because *reasons*.
It's going to come to my player on the night of the new moon, in the darkest part of the night, and impart to him a portion of it's power, but only a tiny portion.
You see, this is the first magic item my party has acquired that is more powerful than a potion or scroll (they are only level 3), so I don't want him to get a flat +1 weapon. instead i want a kind of Legacy Weapon...
I'm debating what to give him for the first perk though, something below +1, and then it would just *grow* as he gained favor with the great old spirit of the night.
So: Debate which of these powers seems like a good first step?
>The axe grants the user one extra first level spell slot, which only refreshes after the moon rises.
"my blessing is not without value, accept it and you will find power."
>Once per short rest, when you crit with this weapon it casts Command on its target with the word "grovel", DC 12
"They will plead at your feet, whether they deserve mercy is your choice. I will watch,"
>The bearer's vital signs, such as a pulse and breathing, are masked by this weapon and are undetectable by non-magical inspection.
"The darkness can hide many things... perhaps you could be one of them."
Of course, after a few more game sessions, it will become a regular +1 weapon, then slowly gain more minor / major abilities as he levels, but, do you like the idea?