Hunter Main?

[Amatsukaze]

Tsuki Gekka only seemed viable if you had a high pp pool, Hatou hardly saw daylight because of how situational it seemed and Kanran was only good against trash mobs.

This is coming from some with a pretty bad katana at the time though so experiences may be different :C

For all I know if you have a niec Katana you could probably Kanran and Hatou anything with little draw back.

[NovaanVerdiano]

Tsuki Gekka only seemed viable if you had a high pp pool, Hatou hardly saw daylight because of how situational it seemed and Kanran was only good against trash mobs.

This is coming from some with a pretty bad katana at the time though so experiences may be different :C

For all I know if you have a niec Katana you could probably Kanran and Hatou anything with little draw back.

Yes, Tsukimi+Gekka requires a fair amount of HP in order to spam it, Ketos Proi can help with that. Hatou can be used in quite a few situations (but of course, not in any) if you get the positioning right and yes, Kanran is for trash.
Katana doesn't really have PAs which you can use for everything, but each PA has their use in certein circumstances, which is something I really like.

[TaigaUC]

Mah class guide may contain useful info.