There are a couple scrolls you learn later if your a wizard. I won't tell you where due to spoilers, but dethrone and a upgraded level 6 magic missile that does nearly 100 dmg. With
a staff that gives free casting, and tadpole free cast power, and amulet of spell slot restoration
you can cast 4 level 6 spells a battle doing up to 400 damage every long rest. It's busted
You are thinking of Art of War which is a level 5 evocation spell. Not level 6.
Tadpole frecast let's you cast a spell without costing you an action. The Markoheshkir staff lets you cast a spell without using a spell slot but it still takes an action, big difference. According the wiki, there is no staff that straight up gives freecast.
The Staff is definitely strong but I would not call it OP compared to the legendaries melee characters get in chapter 3. In fact Melee characters tend to get better weapons throughout the game. The only other good staff in the game, spellsparkler, you get much earlier. You essentially can keep your gear as a wizard the same through 90% of the game.
The same gear on a sorcerer is just vastly better. They can use the twincast to double the damage a wizard would have done. they can use quicken to cast an additional spell for free, they can use heighten to make a spell win a roll against a difficult to hit boss, ect. The only reason to go Wizard was that you can change your spells outside of combat at will but that's rendered moot by the fact that you can respec at any time in this game. A sorcerer in BG3 can essentially change their spells at will so you might as well go that class and get it's other benefits as well. Yes sorcerers cannot learn the 2-3 hidden spells in act 3 but TBH those are nowhere near enough to make up the difference between the two.
On top of that wizards are not great feeling to play throughout most of the game. They are outshined in the game until the end of charpter 2 and mostly serve as utility pieces and CC. Single target damage cannot touch a well geared fighter that gets a minimum of 4-5 50 dmg+ swings per turn except in the instances where enemies are grouped or line up (which is CC as mentioned above) Compared to BG2, wizards in BG3 pale in comparison. So much more fun to play wizards in BG2 or any mage class in Divinity Original Sin 2.
The only redeeming quality might be that wizards typically tend to have an advantage when discovering the secrets of whatever that necro book was called. That is completely OP and should be nerfed.
