This problem has been resolved, and you are now able to access the game.
Greetings, this is Shadow Arena.
There is currently an issue where players are unexpectedly disconnected from the NA server.
We apologize for the inconvenience, and we will do our utmost to provide a more stable service. Thank you for your patience and understanding.
[Notice] [Dev’s Play] Spend Thursdays with the Devs! 2020-06-11
[Notice] [June – Week 2] Hero Rotation 2020-06-11
[Notice] 6/11 (Thu) Regular Maintenance and Website Maintenance (Modified) Last modified: 11. 6. 2020 15:25 UTC+9 2020-06-10
[Notice] Measures Taken Against Violators of the Terms of Service (June 10, 2020) 2020-06-10