Mythical Beings cards on the Polygon Network!

1. Overview.

An NFT is a “digital object” that inhabits a decentralised ledger, a blockchain. Its use has all the advantages that this digital technology provides, in particular its ease of transmission, its full possession by the owner of the private keys, and the possibility of being created under a transparent and verifiable code. However, there is a cumbersome limit to this technology, and that is that blockchains do not communicate easily with each other. Because of this, an NFT created on a particular blockchain cannot, normally, be used on platforms that are based on a different blockchain, and this fragments the NFT space and leads to the loss of useful synergies for all actors, including collectors.

2. The smart-contract.

The smart-contract will be open sourced by Jelurida and made available to the community at a later point in time. Here is a simple summary of how it works. If you would like to know more, just get in touch through the usual channels of Tarasca or the Ardor community.

A. Card creation.

B. Blocked accounts.

The bridge node operates two accounts, one on Ardor and one on Polygon, where the cards will be blocked. The Ardor Blocked Account (ABA) is a new account that starts with a zero balance. The Polygon Blocked Account (PBA) is the account that has created all the cards in that chain, and starts with a balance equal to the entire supply of the collection.

C. Linking accounts.

The smart-contract is developed in Java and running as Ignis lightweight contract, which will control both the ABA and the PBA, so that it will only unblock cards on one chain if the user has previously blocked cards on the other. The smart-contract resides on Ignis and directly controls the ABA and PBA.

D. Ignis to Polygon: address as attached message.

E. Polygon to Ignis: custom deposit address.

3. Operation and uses.

This design of the bridge, although the technology is somewhat complex, created the possibility to offer you, our user, a simple to use interface. We find the result remarkable: the whole process is triggered with a few clicks from within the Mythical Beings wallet, or directly from within OpenSea, and only takes a few blocks to confirm the transactions on both chains.

  • A user has a account.
  • And also has an account on OpenSea, where he wants to trade his cards. These accounts are usually managed by Metamask or other Ethereum wallets.
  • The user accesses the “Bridge” section of the wallet, and chooses the option “Send to Polygon”. In this section, they select the card they wish to send and the amount, and paste their Polygon address in a box. Just click on the send button, and wait a few minutes for the contract to do its job. The cards will automatically appear in your OpenSea balance.
  • Open an account on
  • Access the “Bridge” section of the wallet, and choose the option “Send to Ignis”. A personal Polygon address will appear, the deposit address, to which they need to transfer the cards.
  • In OpenSea: Send as many cards as you want to that personal deposit address. Once they are sent and confirmed, you click on the “Start Swap” button in Mythical Beings, and the smart-contract will take care of everything. Within minutes, your cards will be in your Ignis/Mythical Beings wallet.

4. Effects on supply.

As explained above, the supply of each card remains unchanged, although cards can now live in two different blockchains. In particular, the supply of each card is as follows:



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Mythical Beings

Mythical Beings


Mythical Beings is an NFT card collection game. Every card and creature is unique and has an ancient story. You can collect, buy, trade, and craft cards.