These sort of got lost in the shuffle during the whole Highwind commission thing. In truth I'd had them near-done for a while and only just needed to add the final glowy bits, but never really had the time to sit down and do so.
The irregular cathedral door-like pattern picked out on the sprue was sort of a happy accident. I'm a bit of a pack rat, and so I hold on to sprues forever. When I was searching through my bits box for detailing ideas, I hit on the patterns instantly, rorschach like. Cutting and fitting them to roughly hexagonal facings took some doing, but was by far easier than the initial measuring/cutting/gluing of the plasticard boxes that lie beneath.
They got the standard "oily metal" treatment Tin Bitz drybrushed with Boltgun Metal, darkened with multiple of black paint washes. I've come to prefer the actual black paint to the packaged ink washes; it comes off grainier and sticks to recesses better. I decided to further highlight their weird geometry by placing the glowy bits in places where the needly sprue nubs create frames, rather than paying attention to the hard outlines themselves.
One of things that makes a Mycetic Tomb better than the standard drop pod is that it seats twenty little buggers or one big monster, and so by necessity it has to be a bigger model. Initially I fretted over making something so much larger, reasoning that people would cry foul, but honestly, you have to be realistic about scale with regards to transport capacity and internal machine workings, even with a the race can bend time and space like Time Lords.
I tried to suggest this by making them taller and broader, yet thinner. They still look heavy and industrial as hell though; you get the feeling that the Tyracrons colonize worlds by simply dropping buildings on them (sadly, Mycetics are rather flimsy, stat-wise). I had initially planned to use those rib-like Monolith bits for the Tyrannofex/gun barge, but oh well.
Yes, Grievous looks pissed after his express elevator ride. You would too if you had to fold up to fit in a box that you then ride through the hell of re-entry. Of course, it would have been a bigger stretch if the rules allowed multiple monstrous creatures or something like that. Rules-wise, it would have been nice to have to an initial turn of assault once you bounced out of the thing. As it is, they're only really good for dropping shooty elements like Pyrovores, Zoans, and template-spewing Tyrannofexes.
Of course, as large as they are, I could use them as Monoliths in a regular Necron army in a pinch, but the real strength of the current codex is in Destroyers, anyway.