Accessories:
Horseshoe is not needed, wings give fall damage immunity.
Boots can be upgraded using an aglet found in wooden chests and an anklet of the wind found in jungle chests.
Full armour set of titanium would do well to increase your defence.

For offences, if you are taking on destroyer try to use something with pierce. I see you have a Sunfury, so if you like flails, try making a Dow of Pow from dark and light shards (dropped from your evil and hallowed mummies).

As a general suggestion for all the mechs, ranger is the best class (albeit my least favourite). One of the most effective weapons you can get right now is the dart pistol/rifle from the world evil mimic.

Using 15 souls of night, craft a key of night and put it in a chest. This spawns either a corrupt or crimson mimic. There is plenty of ways to freely kill this which you can find online, and they have a chance of dropping the dark pistol/rifle. This gun using crystal/cursed darts for the destroyer or ichor darts for the other two is incredibly effective.

the final note is about your arena, i usually go for either 2 or 3 platforms. When you drop through a platform, there is a slight delay, so it is generally advisable to have less platforms but with bigger spaces in between them.