What initially held this back was the counter synergy between untapping creatures and the rest of the card
If you've been spending any time in Yu-Gi-Oh circles (or any card game, really), you may have noticed a running joke where Pot of Greed or a card that draws two is mentioned, and someone else would ask "But what does it do?" or something similar
The deck starts by casting efficiently costed creatures with strong secondary abilities including Claim Jumper (land fetch), Finneas (+1/+1 counters, draw), Ghired (creates tokens), Jacked Rabbit (rabbit creature tokens), Mirror Entity (increases base power/toughness), Warren Warleader (rabbit tokens, anthem effect), etc
Whilst its true that you can get away with more than a few best in slot cards in a casual deck, particularly if theyre on theme, the easiest way to strip back the power level is to not indulge too greedily
You'll have to hope his typing gets support or be satisfied with several interchangeable cards that don't synergize with each other any better than several other blue Digimon
So, not only can Brimaz produce tons of incubating creatures but he can also make them bigger