As I'm unaware of every Creon unit out there, I'm simply going under the assumption of the Cavedog version. IF by some chance the following creations are already available in some form or fashion, please point me (and the other readers) in the right direction. I'm sitting here watching an Anime called "Steam Boy" and I've had a couple of ideas, silly though they may be. Feel free to criticize as you see fit...
1 - Steam Trooper - So he needs a better name, but he's rather akin to the Automaton in steam-propulsion and being non-living human (i.e. robot). Basically, a chap who fires a steam-powered net over his enemies at close range (paralyzing them temporarily) while he waltzes in and bashes them with... something. The idea is to give Creon some more close-range/melee units. I'm thinking he doesn't have personal mana, but a rather lengthy reload time on the steam-net.
2 - Scuba Trooper - Those guys who are head to toe in a giant wetsuit with the big bell helmet with an airhose... yeah. Something like that. Slow (but faster than an Automaton), amphibious, general melee. No GREAT need for him, but trying to give them another melee option.
3 - Sentinel - Smallish critter, about the size a dog might be, but he's a scarab-looking sort. Clings super well to surfaces (i.e. climbs anything, even walls... if possible), tough-ish, scary metal pincers do tremendous damage to buildings, decent to units. Short range steam 'spit' where it vents some built-up pressure, super slow reload time.
4 - Magi-Tech Warrior - Think Mechwarrior meets Creon Sage; chain-sword in one hand, gatling gun IS other hand. The gun would fire 4-5 times before falling silent for a time to reload/cool; the sword does about 1k damage per swipe, the gun does a total of 1-1.2k including all rounds.
5 - Discombobulator - A defensive structure; the Sage's Tuning Fork on top of a tower, middling range. It has the same mind-control attacks as the Harpy or Mind Mage; 3-4 shots with 20 second-ish 'reload' time in between before mana runs out.
And now my eyes hurt. Good night!