You know, that thing that Alpha Squad went into?
I originally got this idea from that one knight that constantly says "They came from the darkness" while twitching uncontrollably.
An interesting story idea would probably be to have Alpha Squad be brainwashed or mind-controlled into thinking that we knights are their enemies. Assuming the core is this powerful to do this.
Alternatively, this Core boss could spawn nifty darker copies of ourself that copy our gear and attack us randomly. Surely you were able to take this idea with the Rhendon NPC to allocate with ranged weapons and Mechaknights alike for close combat weapons. Upon defeat, we could have a 3 second period to get enough distance away from our copies before they blow up like the Blast Cube series.
I dunno, I thought this was a nifty idea.
That is supposed to be a reference to the Swarm, which spawned the Shadow Lairs we currently have.
Dopplegangers would either be too easy to fight or the original player versus player all over again.