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?
A casual remark by one of the party about something met on a previous adventure leads to a summons to and grilling by the Mages' Guild (or equivalent), probably resulting in an expedition back to that area to recover the things for 'study' by the Guild. The party's presence will be 'requested' for this expedition.