The guardian's coming along swimmingly (I started on it earlier since GZDoom 1.0.30 was released today).
I found an odd bug, though. If you damage him while he's summoning seekers, he won't move with A_Wander when he returns to the spawn state. I have no idea how to fix this, though
. Also, I don't have too many ideas on how to get the seekers to alert the guardian. I was just about to go dive into my list of ACS functions to find something for that.
Other than that, it's going pretty darn well.
Edit: Okay, here's a beta of the guardian: http://www.zshare.net/download/622464434686c6/
. Again, please don't use it in your wads until it and the seekers hav real sprites and sounds. It has two, maybe three, problems. The first is that after you damage it, it won't move for a minute or so for some reason, and the second is that it might not spawn more seekers for some reason. I have absolutely no idea how to fix either of those, for the moment. The third problem is that it's really hard for the guardian to melee a player when a seeker spots it, but that'll probably be resolved with a smaller map.