Technology in the Cosmic Era can become corrupted and infested. When this happens to a mecha, the result in codenamed a Hekatonkheire.
The Suit of Purity appears to be one designed for the heroic, but it masks it’s true villanous nature. Anyone who wears it for long is bound to be slowly twisted to the Dark Side.
In seeking to escape serving the Lord of Ravens many a hope flickered and died, for those who oppose him end up serving him after all.
A fine suit of armour that provides protection, but from what?
Mining in a certain area turns all exposed skin (maybe just parts that are actively disturbing the chemicals that cause the reaction) of the those doing the mining to a dark blue color. Will wear off taking as many years/days spent in the mine. ... meeting a party of blue-skinned humans armed with pick-axes etc. Strange disease? Demon offspring? Curse? If they meet only one ex-worker, they will very carefully listen to any stories he says, no matter if drunken or insane, or just makes up to get a beer.