Wizard

He never shows up in town on his own. Somewhere in the Cavern layer, after the Wall of Flesh has gone down and the world has flipped to Hardmode, a tied-up old man in robes spawns and waits. Walk over, hit the interact key, and the rope comes off. From there he heads for town by himself as soon as an empty house exists. Any valid room works. He asks for nothing special beyond one nobody else has claimed.

Killing the bound version by accident does not lock you out. Another one rolls later. The same goes for the settled vendor: if a Blood Moon or a stray Wyvern gets him, he moves back in after a while so long as there is space.

The bound spawn is a random roll that happens near you while you travel, not a fixed prop sitting in one specific cave, so mapping the whole world tunnel by tunnel is wasted effort. What you want is time spent moving through open underground space.

The Dungeon is the fastest place to farm those rolls. It is one long stretch of open room, and until Plantera dies no new Hardmode enemies spawn in it, so you can run laps without being chased. A Hunter Potion outlines him through walls. The Lifeform Analyzer is one of the few tools that will name him before you ever see him.

The Crystal Ball is the reason to visit. It is a crafting station a large slice of the magic tree needs, and it can be activated for a short buff on top of that. Buy it on the first visit and put it in your crafting room.

The Ice Rod is the expensive line and it is a tool more than a weapon. The blocks it makes are temporary, which is exactly what you want for throwing a floor under yourself mid-fall or sealing a doorway for ten seconds. Spell Tomes matter once you start crafting magic weapons, and having Greater Mana Potions on tap means you can stop rationing them.

The Music Box is how a track collection gets built, since you need a blank one for every theme you want to record. The Killing Deck only appears in Hardmode and only while a Blood Moon is up, so it is easy to miss for an entire playthrough unless you go looking during one. The Wizard's Hat is locked to Halloween. The pylon he offers depends on the biome he lives in, and he will only sell it once he is settled there with a neighbor close by.

Every so often his idle line swaps for a remark about how your fortune is looking. That remark is tied to your hidden luck value, and nothing else in the game will tell you where it sits. Luck moves for reasons you can control, so if you have just changed something you think should affect it, talk to him a few times and read what comes back. It is a crude gauge, but it is the only one you get.

Anything that wanders into town gets fireballs thrown at it, and they leave enemies burning for a few seconds. His output climbs as you clear bosses, so a late-game Wizard is not helpless during an invasion. He is still soft, though, and town defense is your job rather than his.

His generated names are almost all borrowed. Merlyn, Elric, Fizban, Leomund, Magius and Dalamar point at wizards from novels and tabletop settings. Hirael, Maelor and Arwyn are Tolkien elvish. Xanadu is the Mongol summer capital and Sargon was an Akkadian king.

The dialogue runs on the same fuel, from the jab at friendship being magic to the running gag about the Angel Statue doing nothing no matter what you try on it. He also mixes you up with townsfolk of the same gender and cannot recall whether a Princess lives nearby, which reads as either bad eyesight or deliberate characterization.

Dunking him in Shimmer changes his sprite and nothing else. Another dip puts him back.