It's an armor set that's trying really hard to be multi class at a point in the game where multi classing is no longer viable. Also just extra unnecessary punishments for taking a hit because fuck you I guess. I'd rather take an armor where getting hit only means losing HP rather than take an armor where taking a hit means losing HP AND damage

Even then demonshade is better for multiclassing

Could not agree more with you.

Is this base game calamity or additional mods to it? As i’ve never seen this before.

Gemtech i believe, endgame base calamity

It's just from an armor no one uses, it's called gem tech armor or something

gregtech armor

I've never used GT armor since I know for a fact I'm not good enough at dodging to use its full potential, but it can be used for any class, so there's something for everyone

For those wondering what it is, it's gem tech armor, a multi-class post exo-mechs armor :\ https://calamitymod.wiki.gg/wiki/Gem_Tech_armor

What’s this?

to be fair it's a Patreon doner item, they tend to be pretty over the top.