I thought of a cool boss to add, The Unravaler. 
This is when it starts, and it’s meant to be a post Weaver fight. kaiakairos can decide details, like the next armor tier, but I thought a new boss like this would be cool. After it hits 4k health, it has 6k health, it becomes this 
It’s attacks in the first phase, is dagger attack (melee), a single lightning strike to where the player is, and a fire bullet at the player. Phase two, He can punch you, do several lightning strikes, rain fire, and do fire beams.
Drops: 1 Rock Candy 
1 Platinum Trophy, and 30 Brown Fur 
This leads to the Furry armor set, and tools. The rock candy could upgrade your hp a little.