Tome of Infinite Wisdom

Ogre drops it during the Old One's Army, and Ogres do not appear until the event's second tier, which itself needs a mechanical boss dead first. Worth knowing before you grind: the third tier drops it less often than the second despite being the harder fight, so there is no reason to push up. Stay on tier two until you have one.

Left click fires a tight burst of pages that move fast and stop at the first thing they touch, enemy or wall. That is your single target mode and it is the one you use most of the time. Right click sends out a tall tornado instead, and it changes the weapon's job completely. You swap roles by swapping mouse buttons, without opening your inventory.

It hugs the floor and runs along it, ducking under low overhangs a shot would normally clip. It pierces without limit and lasts a few seconds before fading, and a solid wall is the only thing that ends it early. On flat terrain it sweeps the full height of a corridor for its whole run, which is exactly what the event lanes it was designed for need. The same trick shreds The Destroyer if you can fight along a floor, comfortably enough that it holds up in Master Mode.

The tornado strips vegetation on contact. Sweeping it through the Jungle or across an evil biome clears the plant cover far faster than mining does, which is the quickest way to expose flowers for herb collection or to spot Life Fruit that would otherwise be buried in foliage.

Mythical is the best roll. As for where it came from, the whole event is a crossover, and this wand is lifted from Dungeon Defenders 2 along with its name. The right click is the Apprentice's tornado ability from that game, reusing an animation Terraria already had. Only a handful of weapons here have a genuinely separate right click attack, and three of the others also came out of this event.