When should I unlock new character?

[I0ri]

I heard that it is better to play the characters that is given at the start. Only until I complete story and reach level 60 than I unlock other characters and they will be immediately level 60 with most masteries unlock. Is that true?

Another question is I like Narmada a lot but I heard she is C tier. Is it still strong enough to complete game in normal difficulty?

[パンダ（Φ ᆺ Φ）]

You can unlock it whenever you want however if you unlock it at later stages of the game, once you completed the story until the very end which is chapter 0 then you will unlock the character at level 60 which comes with around 50% masteries unlocked

both the level and mastery points are to be honest very easy to get once you are able to do mission on maniac difficulty so it depend on you is it worth the wait? for me it is not because I would rather enjoy the story with the character that I like and that makes me understand how to play the character better.

every characters is strong if played correctly and you are able to finish the story with anyone on any difficulty.