This pen does not have a feather and requires no refill from an inkwell. In fact it would only be considered a pen in name and function, most would not recognize it as a pen at all. It appears to be a thin metal rod the length of a man’s hand and decorated with gold inlay. To attune to this pen you must write your true name, not an alias or nickname, 100 times on a piece of parchment or paper using this pen.
While attuned to this pen you may summon it into your hand at any time as an action, and you know the cantrip Vicious Mockery. While holding the pen Vicious Mockery does an additional 1d4 damage.
Additionally, once per short rest you can cast the spell Skywrite with the pen, ignoring concentration.
This pen has yet another special property though. As an action you can create a symbol on the top right of a piece of paper or parchment that is unique to you. This symbol is the same each time you create it. You can accompany this symbol with a number and/or the name of a creature if you so choose. When you write or draw on a piece of paper with your own symbol ink begins to form in an exact copy on all other pieces of paper that share the same symbol and number combination, as long as they are on the same plane of existence.
Paper that has the true name of a creature accompanying the symbol will appear blank, except for the symbol and name in the top right corner, to all creatures except those that have that name.