Allmage

During the casting of this spell, you inscribe a triskelion of at least Huge size on the ground. The target of the spell is one of its casters, who stands in the middle while the other three stand in the center of each swirl. One of the three holds the spell scrolls, another holds the hands, and another holds the weapons. The target must be within range of all casters for the casting time of the spell.

When the casting is complete, magic is drained in a 1-mile radius, which falls under the effects of an Antimagic Field, and each caster except the target must make a DC 20 saving throw using their spellcasting ability. On a failure, their maximum number of spell slots for each level is halved, and they lose any excess slots gained through other means. This can only be reversed with Wish or by being the target of this spell.

The target adds every spell known to its spell list, has an unlimited number of 1st, 2nd, and 3rd level spell slots, and gains an additional 6th, 7th, 8th, and 9th level spell slot. The target can immediately change some or all of its spells prepared or known with every list available.

Additionally, the target of this spell loses its hands, which are replaced by the hands used as components of this spell, changing in size as appropriate. Finally, the target gains proficiency with the weapon used as components.