Unsurprisingly, Detlas does the same as he always does, much like a single-minded golem or beast of burden. He wakes up early, patrols the ship to make sure everything is in place, consumes a heavy but basic breakfast, and begins his strict training regimen. He always skips lunch, eating small snacks throughout the day during his short breaks. The majority of his training is intensive core work and cardio, with plenty of muscle-building. Assuming that Jonathan is still offering his services as a teacher, Detlas also sets aside time for unarmed training sessions.
The end of his day is marked with dinner, and him quickly returning to his quarters. Presumably for sleep.
Unarmed 49/70 or 39/70 if Jonathan is not teaching
And as the feast comes his schedule hardly changes. He adds just a few new things to his meals, but eats nothing more than that. Days are still spent training. Come evenings, he sticks around for maybe half an hour before going to his quarters.
And he doesn't drink the wine.
He only drinks from a very plain looking canteen of everflowing water. In fact, he's only drank from that canteen. He's had it when he was found on the floating rock, and he's had it on him ever since. Detlas has drank nothing else, and drank from nothing else.