Not very impressed by the eth bridge. This could have been done on your own database, it could even be done on hive without smart contracts by having local bots do the work and using hive with parentpermlinks as pack or card types, and normal permlinks as a lookup table to link packid[or cardid] to owners, or possibly done on vsc if you really really wanted smart contracts.
Good luck on your eth/b3/whatever project.