Zenimon BT18-059 by yuuki., Wisemon BT18-068 by Ryodan, and Mercurymon BT18-064, Sephirothmon BT18-066, and AncientWisemon BT18-074 by Tomotake Kinoshita from BT-18 Booster Elemental Successor (BT18-19: Special Booster Ver.2.0)

seen from United States

seen from Kyrgyzstan
seen from France

seen from Türkiye
seen from Argentina

seen from Germany
seen from Germany
seen from Ukraine

seen from Germany
seen from France
seen from Malaysia
seen from Estonia
seen from China
seen from United States

seen from Malaysia
seen from Saudi Arabia

seen from United States

seen from United States
seen from Sweden
seen from United States
Zenimon BT18-059 by yuuki., Wisemon BT18-068 by Ryodan, and Mercurymon BT18-064, Sephirothmon BT18-066, and AncientWisemon BT18-074 by Tomotake Kinoshita from BT-18 Booster Elemental Successor (BT18-19: Special Booster Ver.2.0)
Made Zenimon last year for my store, but as I can't find any reference for his back I've been putting it on hold. Maybe he'll appear in Time Stranger and we'll finally find out if he looks like a 5 yen coin from back, too! Anyway, other than needing some adjustments to the print, this was a fun and easy one to make. I'll add him to the store soon!
Zenimon BT18-059
BT18-059 | Zenimon
Rookie | Vaccine | Mutant
Common | Black
So a fun discussion in the Digimon reviews @bogleech did was Steel's link to magic, mysticism and alchemy and the booster set Element Successor seemingly reinforces this by making Zenimon the Steel line's Level III stage.
Edit: alternative idea suggested:
Zenimon
Smash
Pass
Best Rookie: Round One
Zenimon
Bun
Gaossmon
Bracket 10/64