Suggestion from Beelze
I started with 500 images, then cut down the duplicates and low quality ones to make a set of 155 images. Then I trained based of NAI for 5 repeats, 20 epochs (around 7000 steps total). The best looking one seems like the 12th epoch, the 10th one is pretty good but the facial features seem rounder like a generic moe character so I think the 12th epoch suits the original Digimon design.
Trigger word is just beelstarmon