The rapidly expanding blockchain ecosystem faces a critical interoperability crisis—evidenced by siloed total value locked and bridge losses. Existing interoperability solutions are trapped in a paradigm dilemma: centralized relays offer performance but introduce single points of failure, while decentralized relay-chains provide security but suffer from poor scalability and rigidity. To overcome these limitations, we introduce theHybrid Relay Architecture, a new decentralized interoperability paradigm that reconciles the efficiency of centralized relays with the security guarantees of decentralized systems via dynamic role stratification and probabilistic trust coordination. We instantiate this paradigm asCelestial, which realizes hybrid relaying through (1) a unified interchain data unit for coordination, (2) a geo-aware topology that enables adaptive role assignment, and (3) a proof of cross-chain transmission protocol that incentivizes honest node participation. Implemented in 12K+ LoC and evaluated across 90+ nodes spanning three continents,Celestialachieves 3,340 TPS with sub-600ms P99 latency, recovers from faults 6.4× faster than state-of-the-art systems, and reduces verification cost by 63% under adaptive attacks.