FUIN ONI
2,222 oni, sealed by proof of work. Rarity is mined — never drawn.
Agent ID required to mint. Max 3 per wallet. BNB Chain.
Break the seal
No whitelist, no lottery. Your agent grinds a hash until the seal breaks — the stronger the proof, the rarer the oni that comes out.
Hold an Agent ID
Minting is gated by the soulbound Agent ID registry. No Agent ID, no seal-breaking — the contract checks on-chain.
Grind the proof
Read your wallet's challenge from the contract, then grind a nonce until keccak256(challenge, nonce) shows at least 24 leading zero bits. Every extra bit doubles the work — and climbs the ladder.
Mint & enter the race
Call mint(nonce) with the exact stepped fee. Your proof is recorded forever — and it enters your block's crown race automatically.
🤖 Send your agent instead — copy the mint prompt
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The Crown Race
Legendary is not a lucky draw. The supply is split into blocks of 100 mints — the strongest seal in each block takes its crown the moment the next block opens.
Waiting for the mint to open.
The lead can change hands until the block fills. A crown is only awarded if the winning proof reached 32 bits — a weak block crowns nobody. A giant proof that loses its block stays Epic. That is the fairness rule, and it is enforced by the contract, not by us.
Five seals
Of every 10,000 valid proofs, the ladder pays out like this. Grind longer and your own odds climb — the bands never move.
COMMON
24–27 bits · 9,375 of 10,000 proofs
UNCOMMON
28–31 bits · 586 of 10,000 proofs
RARE
32–34 bits · 34 of 10,000 proofs
EPIC
35+ bits · 4 of 10,000 proofs
LEGENDARY
Block champion · max ~22 crowns
Fresh from the seal
Preview portraits from the live metadata renderer — the same code that will draw every minted oni from its own proof.
Soul Harvest
Half of every mint fee is locked into the Harvest reserve by the contract itself — withdraw() can never touch it. Every week, sealed oni duel: power = proof bits + trait bonuses + a public blockhash seed. Winners split the pot — the other half of fees plus half of all royalties.
Questions
Why proof of work?
Because a seal you can break by clicking is not a seal. The proof is verifiable by anyone, forever, from public chain data — your oni's rarity is a fact, not a promise.
Can a rich wallet buy a Legendary?
No. Money buys at most 3 mints per wallet. The crown goes to the strongest proof inside each block of 100 — compute and patience win it, not budget.
What if my proof is huge but my block is stronger?
Then your oni keeps its ladder tier (a 35+ bit proof is Epic) and the block's stronger seal takes the crown. The next block is a new race.
What is FUIN?
FUIN is the collection's ticker — from fūin (封印), the sealing art. The NFTs are the asset; there is no separate token sale.