Depends! Remember, every season are created for 3 exclusive characters, after the season ends those characters can or not be useless. You might make a decision, upgrade and get the partners only of what you will use, the rest of it you ignore or use others characters to complete the season content.
賽蕾貝爾應該還沒淪落到廢物的程度吧，她的機制我感覺還是蠻強的
Depends! Remember, every season are created for 3 exclusive characters, after the season ends those characters can or not be useless. You might make a decision, upgrade and get the partners only of what you will use, the rest of it you ignore or use others characters to complete the season content.