Trained on animefull. Trigger word is: setethFE.
Default appearance: setethFE, uniform, garreg mach monastery uniform, cape, beard, circlet, long sleeves, boots, belt
Having both "uniform garreg mach monastery uniform" in the prompt helps especially with full body shots, otherwise some gens may give him white pants instead.
Bonus: Use "1boy, 1girl, father and daughter" to get a free Flayn! I had good luck with that in my gens at least, your mileage may vary.
Weight 0.7-0.9, start at 0.8.