It is Important to see how the Kit of the FFXIV Samurai emulates real Samurai principles:

Kaiten - Is to utilize the Breath, to breath into every attack to make it stronger
(which is why the Samurai since 6.1 feels so weak, they doesn't utilize the breath anymore to wind up.)

Single Target and AoE Variants that utilize the same resource:
Guren/Senei , Shoha/Shoha II - that emulates the spacial awareness, to see the situation and use the correct techniques to win. When I'm surrended, I rather utilize my resources to hit all my enemies and when I'm in a duel I let hell break loose with strong targetted attacks. There was an oddity brought up, how we only one skill per New Resource.. after thinking about it, I'd say it to emulate the Journey to discover new techniques and perfecting them with the AoE / Single Target Variant in the Next Expansion+ learning something new to repeat the circle of learning and perfecting.

Ikishoten - launched in Shadowbringers, I'd say it's a preparation stance, because Guren and Senei have the same Cool Down so it perfectly lines up+ ikishoten also activates the Ogi Trigger.

Hagakure - it's a Code of Honor of the Samurai and the constant awareness of death, which is why in FFXIV it flushes away all your Sen for additional Kenki. It's in my opinion the more situational brother of Kaiten since Kaiten takes Kenki and Hagakure gives Kenki, through the sacrefice of Sen. (sometime ago I had a conversation with a friend about Hagakure, though in the context of FFXIV it's to have presented as a Skill)

Meikyo Shisui - It's the shortening of Techniques to perform them faster. (Something my Aikido Master showed me long ago)


BONUS - recently I watched a JoJo's Bizarre Adventure Allstar Battle R Super Combo Showcase Video, there my Favorite Character: Gyro Zeppeli used Ogon no Kaiten! ... so you'll tell me.. that my favorite Character, who made me love Pizza Mozzarella also used Kaiten!