I think the Zenith just needs to be reworked. In fact, the whole Melee class in general is just a complete mess!!! To start, I think the swords should act similarly to how they do in the terraria overhaul spoilers. They can be aimed, swung up and down in that order, and even bump you in the air when you damage an enemy. There should also be some new types of swords, like one that dashes through enemies or maybe an extra hitbox with different stats.
Second, and I kid you not, less projectile swords. This one might be a slight stretch, but there are too many projectile swords that just defeat the purpose of a melee weapon. There are some weapons that I think should keep the full projectiles like the Enchanted sword, Star Fury, Star Wrath, and Terrablade. Even if removing most of the projectiles is too much, I think they should at least get a distance limit. Make it so that they only go for like a couple blocks and then disappear?
Third, I've always had a weird feeling that melee needs a new subclass. One time I thought of Melee hooks. They look like regular grappling hooks, but they instead deal a small amount of damage and pull enemies in to close the distance. Any enemy that gets pulled towards you cannot attack or perform any action while and a little bit after being grabbed by the hook. Also, any enemy with 100% KB resistance will instead pull you towards it and let go when right next to it.
Lastly, a Zenith rework *GOD IM GONNA GET SLAUGHTERED FOR SAYING THIS!!!!" My main issue with the Zenith is... pretty much everything about it. It requires no mana/ammo. It can go anywhere on the screen. It goes through blocks. Its insanely easy to use. It shoots a bazillion swords at Mach 10 with. It ignores enemy I-frames. The list goes on.
Here's how I would change it. First I would make it act like an actual sword with a base damage off 1000. Ik, sounds dumb, but that's only the blade itself. It would have a use time comparable to a Muramasa. Every 3 swing, it would shoot 3 vanilla Zenith Projectiles to keep it familiar and prevent it from being boring. If that sounds to much like a nerf, maybe the Seedler, Horseman's Blade, beekeeper, and one of the Moonlord swords could be removed from the recipe. Probably not.
And THAT ladies and gentlemen is why the Starlight is my favorite sword in Terraria right now! Thank you for reading this forum post!!!
But in all seriousness, Melee is just begging and praying for a cleanup. Its weapons are weird, it isn't smooth through the whole game, and it is very deceptive, tricking me into choosing it when I first beat the game.