the red armour
@Eversor: The big chin is a collar and why shouldn't there be a power armor, that doesn't look like that? The armories of the Space Marines have many different kinds of armor and not all fall into the eight main categories.
Could that be Cypher? You know that fallen one that the Dark Angles and their successors want to capture most all of the fallen? They even request a new founding chapter from the council of Terra on the sole purpose to capture that guy.
also @Eversor it could be Mk V armour since all Mk V armour was what the Techmarines could cobble together from parts of earlier marks of armour to make battle ready power armour as a stop gap measure to make up for the fact that Horus managed to subvert the majority of the martian priesthood
i love that you actually included a suit from the emperor's children prior to corruption.
also space marines often have local foundries making customized suits of armor. plus artificer and heresy armor add difficulty to identifying other marks. plus cybernetics being used in place of suit parts. oh and there is about 4 different types of terminator armor
Okay, so...you're essentially butt naked with the exception of a bed sheet and a creepy dude shows up out of nowhere whispering in his creepy tone about creepy things which creeps you out...creepy. I don't like where this is going.