2013 onwards Wakana basically became lead in everything - except blaze… (still my fav) and they became kind of type cast in a way.
Honestly, I don't think it was a case of being typecast,
per se. It was a matter of what was available from the 3 singers and the songs written for them.
Wakana was the lead because she was the only one that could take that soprano range consistently and she had that
tone. That's where them being in FJ showed that range-wise Kaori (and Yuriko, later Joelle) could take that soprano lead but Wakana though was a lyric voice (or soprano) which Kajiura prefers for her classical-leaning songs (Yuuka Nanri, REMI, etc.). Hikaru leading changes a song to be more pop/rock, which Kajiura only required for fewer songs. Yuriko's tracked voice also only worked right above Wakana's in harmony. Kalafina was firmly in the classical/ pop/ anisong fantasy realm, so more Wakana's forte.
Hikaru’s solo career is by far my favorite, demonstrating to me that she’s the strongest vocally (debatable).
More like Hikaru's the most experimental and adventurous with her voice, not the "strongest" in technique or range. She's the most dramatic vocally and expressively, especially when I'm hearing her songs with lower darker range, or covering some of Ado's music with some of that edge on her YouTube channel (both Wakana and Keiko don't have the voices for that).
Keiko’s had the most potential but man, bored me to death.
I have come to have a different idea of Keiko's potential, having listened to her songs in different genres (anisong, ballad, house, pop rock, etc.) and covers of Japanese classics on her channel, and also Kajiura-style "Yuyami no Uta". She's not really strong in the high range for extended notes. Her strength is in the middle and low range, as long as she controls herself to not yell for forced belts or going too dark (and so more swallowed/quieter) for really low notes . There are times I've heard her sing more open with vibrato, but it's intermittent.
The use of mask/nasal resonance is something I wish she picked more from Kaori. Emiko has that. If not for Hikaru losing her upper range, (and her technique issues) I would now say that
she had the greatest potential.
Honestly Kalafina shoulda just been called “FictionJunction KALAFINA”.
Yeah. Maybe if other parties weren't involved in the group's creation. I feel if Kajiura had a second lyric soprano in there as a balance to Wakana, we would have kept her voice health and had a variety in tone.