When you attune to the quarterstaff, it remains solid in your grip but feels pliable within your mind.
Whenever you take the Attack action, you can choose to make your attacks at range. When you do, you can use your mind to telekinetically curve the quarterstaff into the form of a longbow. The bow is magically strung with an arcane energy that arcs between the rings on either end of the weapon. A glowing, magical arrow is drawn into existence whenever the arcing energy is pulled back. The arrow disappears after it hits or misses its target. When you make a ranged attack with the quarterstaff in this way, the weapon is treated as a magical longbow that uses your intelligence modifier for attack and damage rolls. This longbow can only use the ammunition that it generates and does not have the heavy property. While you're attuned to the arcanist's bowstaff, you're proficient with this longbow when using it in this way.
You gain a +2 bonus to attack and damage rolls made with this magic weapon in its bow form.
In addition, the quarterstaff has 3 charges which it regains after a successful long rest. Whenever you take the attack action, you can expend 1 charge to immediately cast magic missile at first level as a bonus action, with each bolt targeting the same creature as the initial attack. When you do, the missiles fly from the drawn bow in rapid succession after the arrow.
Proficiency with a Quarterstaff allows you to add your proficiency bonus to the attack roll for any attack you make with it.
This weapon has the following mastery property. To use this property, you must have a feature that lets you use it.
Topple. If you hit a creature with this weapon, you can force the creature to make a Constitution saving throw (DC 8 plus the ability modifier used to make the attack roll and your Proficiency Bonus). On a failed save, the creature has the Prone condition.
Notes: creature with an Intelligence of 17 or higher, Versatile, Topple