0x25346425353425343525333525343325366125343525373725346425353125366625373825346425343425363725346225346625353425366225346 2253464253534253435253738253433253661253435253737253466253531253666253738253464253434253435253462253464253534253435253332 2534332536612534352537382534642535312536662537382534642535342535352534622534642535342534312533302534332536612534352537372 5346525353125366625373825346425366125343525346225346625353425363325346225346425353425343525373725343325366125366225333425 3433253661253662253333253433253661253435253738253465253431253364253364
Because it is the beginning of the 0x, it is hexadecimal with Python binascii.unhexlify
Similar to mte5cjewmqoxmdgkotk%4
URL encoding is thrown to the URL decoding interface Http://web.chacuo.net/charseturlencode and gets a string
xcjewoqoxmdekmte2cjexmqoxmtukmta0cjewnqoxmjekotckmtewcjk4cjk3cjexna== look at the back two equals sign is base64 and decode to get the final flag Welcometoshiyanbar
URL encoding base encoding decoding hex