From this 3 would i say the reaper.
The ninja can be a pain with his jutsu (did you make a error or the system didnt recocnice the right button, is the bunny coming and you lost attack for the moment). He was ok in shb. But feels a little weird in the 80er-90er area. At last have i trouble to use the chidori and Raiton correctly (raiton create a buff for chidori, but vanish, of you use weapon skills).

Samurai feels a little to stiff for my taste. The animations looks a little boring. Because he move very little. And it feels like, that he has nearly no reach with his sword (esspecial his aoe has a low reach). And, because he has 3x 3er combo, can it be questionable, how to place the skill for a good flow.

Reaper is mostly fast and has nice animations. But has the feeling of small reach to. And, based how you Set up your skills, can your finger hurt, when you need allways the shift button to, for your skill (dont know, how it looks on the controller).

If you want to add more classes, could the monk or dragoon maybe be nice. Monk is fast and very forgiveable with the skills and feels easy to use. Its only a little pain, that he has no normal distance attack (aside of chakra use).
And the dragoon is corrently the most streamlined class. And his skills feels as the one, who connected as the best from skill flow. And, has with his aoe a little more reach, as the other. But, the dragoon will have a rework next year. And could maybe change very strong (if it is like with the summoner). Or only a little (if it is, like with the monk, compaired to the 5.5 version).