Amongst the most difficult races in my world to make ships for are the Zegredark Templar and the Zelconian. The Zelconian's smooth, exotic arch-based architecture makes for an impossible challenge to my juvenille abilities. The Templar are less complex, but their blackened hulls are still very smooth and very much alien in comparison to both the Anahn and Undead whose designs I am more familiar with. Neither the Zelconian nor the Templar use conventional-styled weapons. Templar use a mixture of psionic based weaponry, external "drivers", and elemental crystal focuses, usually Lo`Aummaeth that appears as glowing emeralds embedded into their ships. Zelconian have a few phaser-like drivers that fire bright blue Proteus elemental beams or pulses, and their omni-directional weapons have yet to be visually developed in my head at all.

A conceptual attempt at using symmetry to turn the Hydromek revision I have into a Norkozad. This model is considered a failure as it cannot reach even partial similarity to the design in my head. The Norkozad is one of the prime Templar battleships. Modeling it would be considered a colossal success, and for good reason - it is amongst the hardest of all models I've ever attempted. Failure is to be expected at every turn.
Another difference is that Zelconian ships are much smaller than Anahn ones. Templar warships are typically monstrously larger, as their technology is considerably more advanced than either race. Ingame these scales obviously can't be reflected to-canon, but they will definitely be noticably smaller/bigger.
The most irritating thing I'll have to deal with is the weapon and firing arc limitations in sins should I manage to make any of their ships. Templar ships typically have very weird weapon locations, and these will almost always result in beams/projectiles clipping through hulls in-game. Stuff like that bugs the hell out of me.
As I cannot model the more exotic Undead ships at this time, I've moved back to modeling Anahn ships and preparing to pave the way for Episode 1 content.

This was once the Gahennas Dreadnaught from 2007. It has felt the meaty smack of the Symmetry modifier and awaits being changed into an Anahn fourth-gen supership. Take a good look - it will scarcely resemble what it looks like right now when I get around to mangling it. That may not be until episode 2 at the earliest if I make it that far. No idea what to do with it.

The Alpha version of the ruin. Alpha is basically final in-game variant. There's nothing else I can do to it within my skill level to make it look better.

The Longbow, butchered by Symmetry for a mid-range cruiser later on. Will probably take the place of both the command cruiser and carrier.