By analysing the currently existent jobs I realized that there isn't anything left for Samurai in DPS and Tanking roles without taking serious risks of becoming redundant. When we get to Healing roles though these risks vanish miraculously, yes, I'm talking about:
The Melee Healer.
There is nothing like this right now in this game. Free spot. Rarelly used archetype in MMORPGs, and believe or not, it is compatible with previous cases of this class in Final Fantasy.
By releasing the "soul of the sword", Samurai in FFT were capable of manifesting many different effects depending on the weapon they had. Half these effects were, suprise, suprise, support. Healing, MP recovery, Regen, Haste, Protect and Shell.
With the soul of the weapon, and other possible shenanigans like shouts, auras, and the endless healing power of friendship, Samurai could be the Warriors of the healers, too strong of a dps for its role, still decent on the role it is supposed to fit.
Well, I never designed a class before, so it is totally going to be bad, but I tried something like this:
Class: Samurai.
Role: Healer (Melee).
Weapon: Katana.
Cross Classes: Pugilist & Rogue.
Cross Skills: Mantra, Haymaker, Featherfoot, Second Wind, Internal Release, Shade Shift, Goad.
Abilities
*Spirit Stacks go up to 5.
01 Fang - Delivers an attack with a potency of 130. Grants Spirit stack for 30 seconds.
02 Murasame – (OGCD) Releases spirit stacks, healing surrounding allies by 150 potency for stack.
04 Tiger Slash – Delivers an attack with potency of 100. Combo Action: Fang. Combo Potency: 170. Combo Bonus: Reduces damage dealt by 10%. Grants Spirit stack for 30 seconds.
06 Shirahadori - (OGCD) Marks an enemy and parries next marked enemy’s attack within 5 seconds. Pacifies the enemy for 5 seconds.
08 Masamune – (OGCD) Releases spirit stacks, adding mind to the katana damage modifier for 3s for each spirit stack. Surrounding allies receive 50 potency regen for twice the time.
10 Mineuchi - Delivers an attack of potency 120. Additional Effect: Stun for 3s. Does not remove Sleep from target.
12 Stand - Resurrects target with +15% stats for 20 seconds. Weakened state is applied 20 seconds later for 2 min. Can be used during combat.
15 Ashura – (OGCD) Releases spirit stacks, delivering a ranged magic attack with a potency of 30 on health and mana for each stack.
18 Kiyomori – (OGCD) Releases spirit stacks, removes one detrimental effect from surrounding allies for each stack.
22 Courage – Grants 150 TP to surrounding allies.
26 Dragon Empower – Delivers an attack with potency of 100. Combo Potency: 240. Combo Action: Tiger Slash. Combo Bonus: Applies Dragon Bite that heals anyone who attacks this target by 20% of damage for 15s. Grants Spirit stack for 30 seconds.
26 Kotetsu – (OGCD) – Releases spirit stacks, sleeping all surrounding enemy for 3s each stack.
30 Iainuki – Delivers an attack with a potency of 120 to all enemies in a straight line in front of you, 220 potency if enemy’s hp is below 20%. Moves to the last enemy in the line.
34 Tempest Slice – Delivers an attack with potency of 100. Combo Potency: 190. Combo Action: Fang. Combo Bonus: Reduces target’s magic resistance by 10% for 20s. Grants Spirit stack for 30 seconds.
38 Calm Mind – Reduces enmity by half. Aditional Effect: Fills spirit stacks.
42 Oblivion Cleave – Delivers an attack with potency of 100. Combo Potency: 220. Combo Action: Tempest Slice. Combo Bonus: Heals surrounding allies by 50% of damage, 100% if enemy has Dragon Bite applied. Grants Spirit stack for 30 seconds.
46 Ame-no-Murakumo (OGCD) – Releases spirit stacks, slowing down all surrounding enemies for 3s for each stack.
50 Chirijiraden (OGCD) – Releases spirit stacks, dealing fire damage to all nearby enemies and healing all nearby allies with a potency of 60 for each stack.
Traits
08 Enhanced Mind – Increases Mind by 2.
14 Enhanced Mind II – Increases Mind by 4.
16 Morale – Critical attacks heal nearby allies by 15% of the damage.
20 Enhanced Shirahadori – Shortens Shirahadori cooldown to 20 seconds.
24 Enhanced Mind III – Increases Mind by 6.
28 Enhanced Stand – Duration of Weakness is lowered to 40s.
32 Enhanced Courage – Increases the TP restored by Meditation to 300.
36 Enhanced Dragon Empower – Extends Dragon Bite to 30s.
40 Spiritual Integrity – Spirit releases always keep 1 spirit if 5 spirits are spent at once.
44 Morale II – Critical attacks heal nearby allies by 30% of the damage.
48 Enhanced Calm Mind – Shortens Calm Mind cooldown to 60s.
Job Abilities
30 Bushido (Stance) – Grants one spirit stack every 5 seconds. Increases Mind stat by 20%. 50% of all damage taken by allies is distributed among party members. Reduces Enmity generated.
35 Companionship – Parries all attacks received by surrounding party members for 15s.
40 Kikuichimoji (OGCD) – Releases spirit stacks granting the same number in Sanguine Blossom stacks, the stacks are consumed whenever an ally receives damage, delivering an attack of 50 potency back and healing for the same amount.
45 Osafune (OGCD) – Releases spirit stacks, granting a 20 potency Refresh to all party members for 3s for each stack.
50 Samurai Soul – Next release skill can be used without spending spirits as if maxed.
52 Satsui (Stance) – Attack skills that generate spirt stacks now consume one spirit stack instead, becoming a guaranteed critical attack. Sanguine Blossom stacks are transformed into Death Blossom stacks that no longer react to damage.
54 Zantetsuken – Can only be used with Satsui. Consumes all Death Blossom stacks. Deals 60 potency damage for each stack and ignores defense.
56 Honor – Can only be used with Bushido. Consumes all Sanguine and Death Blossom stacks. All surrounding allies receive Stand effect of +15% stats for 3 seconds for each stack consumed.
58 Determination – Surrounding allies cannot reach less than 1 HP for 6 seconds.
60 One with the Sword (OGCD) – Consumes mana to buy one spirit stack.
Details
About Healing Without Mana: When I did the Monk questline, Erik taught me about how enemies release Aether when defeated. Aether being well, lifeforce, same thing used by Scholars and Summoners to do some miracles. That got me thinking, do you really need your own mana to use magic then?
Samurai being the uh... Spiritual warriors they are, with all the "I can cut anything with these katanas" idea, including cutting souls got me thinking... What if they tear the enemies' souls with each attack, and use it for themselves?
Well, that's pretty much the whole concept of the class above. You rend your enemies' souls with your special cutting skills, drench your katana with their aether, and use the accumulated aether to do magic. This way you don't need mana at all.
Overhealing: In theory, Samurai will be constantly healing the whole party. The overhealing would cause ridiculous ammounts of threat and ruin everything, except for the fact that the healing has a very short range, Battle Litany-like. That means that party members can control how much healing is being done by measuring their distance to the Samurai, same for the Samurai itself. Needs healing? Get closer. No healing? Back off.
Potency Values: I never made a class before, so the numbers are as good as random. I tried my best by looking at the available damaging skills for healers, assuming Samurai will cause a little more damage as I planned it to be something like the Warrior of Healers (everyone knows Warriors are OP). I do think the values I chose might be too much though, regardless of that, it is just a matter of nerfing.
Lack of single target heals: Considered my experience with dungeons in the game so far, healers are barelly required to heal, and when they are required to heal seriously, it is because the tank messed up and everyone is taking damage. I don't see a problem with the Samurai kit for healing, except for specific Raid fights that I'm unaware of how works. The Healing Stance Bushido was one way I found to force things to be more compatible to the lack of single target heals.
An interesting consequence of Bushido is that, since it works in short range as well, the more party members you have close with it active, less damage each individual takes, and more healing is done. Way to go with the friendship power of supporting each other, I think I achieved one of my goals for this class with this.
All the OGCDs: I think it is the only way to make this viable. Differently from others healers, you have to build up Spirit Stacks to start healing, any waste of time can mean too late.
Competition with other Healers: If anything, it tells healers to wake up. Last I got into a dungeon with a healer, my White Mage spamming Stone II and Aero in Cleric Stance had a very solid DPS. Something clearly above 200 potency every moment. Any needed healing can be done with a quick OGCD removal of Cleric Stance and a cast of Cure II or anything.
But that's all optional. Healers might as well just stand there and do nothing until required to heal. That is the point in which Samurai has a different take: You have to do DPS to be able to heal, there is no lazyness allowed.
Naming of Skills: They were all almost directly based on FF6's Cyan's Bushido techniques, FF5's Samurai abilities, and FFT's Samurai's skills (if not almost literally adapted to FF14).