The owner of this website (jp.

The owner of this website (jp.leagueoflegends.com) has banned your IP address (108.61.223.141).  
Used node  JP Asia (Tokyo - Equinix)

It’s possible. :-( And other mudfish nodes could be happened too though.  

getting 502 Bad Gateway since yesterday

Getting [138.440391] re159: MUDEC_00262: ODR_sendto() error to 210.16.120.130: Message too long. Check your paty MTU. (curmtu 1450 buffen 1464) Error

Connection with Tree of Savior (Singapore) has been bad and it is the
same no matter how i change the Full VPN / Nodes. Any idea on how to
solve it?

Did you try to turn off FastConnect mode and Full VPN mode? And what’s your current ping with or without Mudfish?

getting 502 Bad Gateway since yesterday

Is it still same?

Getting [138.440391] re159: MUDEC_00262: ODR_sendto() error to 210.16.120.130: Message too long. Check your paty MTU. (curmtu 1450 buffen 1464) Error

Please check MUDEC_00262 section for details.