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)
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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