Make it a melee DPS capable of casting buff spells (oGCD) that buff themselves in certain ways. The oGCD buff abilities will depend on the route of attacks you decide to go with (like Ninjutsu, but without the server lag). Main weapon will be the rapier, of course.
1-2 combo = En-Ice: Makes all attacks (related to combo) cause Chill DoT. Applies player with TP Regain buff for 15 seconds.
1-2-3 combo = En-Fire: 10% damage boost for 30 seconds, attacks become AoE's (TP of abilities is doubled).
1-3-2 combo = En-Light: Makes all attacks cause Defence down (for 10 seconds, mob immune after) and increases Skill Speed for 30 seconds.
Enspell: Depending on the combo, Enspell will become En-{Element} and buff the player. 60 second cooldown.
There would be other skill combinations (4-5, 4-5-6, 4-6-5) to include Thunder, Water and Dark, but I can't think of them at the moment. Other abilities to think of, too. Like {Element}-Spikes, Dia, Banish, etc.
Level 1 – Combo 1
Level 2 – Dia (DoT, instant cast)
Level 4 – Combo 2
Level 6 - Blink (Evasion up)
Level 8 – Combo 4
Level 10 – Distract (target evasion down)
Level 12 – Spirit Dart (ranged attack)
Level 15 – Comrade in War (DoT on mob + party TP Regain 5 seconds. 60 second CD)
Level 18 – Temper (2.5 second cast)
Level 22 – Reraise (instant cast. Off global cool down. Sacrifice 80% MP to grant a party member with Reraise buff. Buff duration 15 seconds.
Level 26 – Combo 3
Level 30 – Banish (170 damage potency, MP cost similar to Thunder. Dia DoT's have a 5% chance in turning Banish into an AoE)
Level 30 (Job) Enspell
Level 34 – Dia II (2.5 second cast. 50 damage Potency and DoT. Dia DoT's can stack)
Level 35 (Job) Element Spikes
Level 38 - Combo 5
Level 40 (Job) Phalanx (5 second cast. 50% Defence Boost on target for 20 seconds)
Level 42 – Frazzle (AoE INT and Piercing resistance down. Cannot be stacked with Disembowel)
Level 45 (Job) NulAll (Reduce parties magic vulnerability by 15% )
Level 46 - Combo 6
Level 50 – Banish II (240 damage potency, MP similar to Thunder II. Dia DoT's have a 5% chance in turning Banish II into an AoE)
Level 50 (Job) Death Blossom (sacrifice 20% HP to deal 400 potency single target damage. Can only be used in En-Dark)
Level 52 – Comrade in Magic (give 25% of MP to a party member. 120 second cool down)
Level 54 – Refresh (oGCD, 2.5 second cast. Grants user with Refresh buff for 30 seconds. 120 second cooldown)
Level 56 – Accession (makes the next Spike or Barspell you use AoE with 50% less potency. 90 second cool down)
Level 58 – Banish III (damage potency 300, MP cost similar to Thunder III. Dia DoT's have a 5% chance in turning Banish III into an AoE)
Level 60 – Manifestation (extends the duration of all Enspell, Spike and Barspells buffs by 20 seconds)
Enspell – 60 second Cool Down.
En-Blizzard: Chill DoT. TP Regain for 15 seconds.
En-Fire: Damage Up for 30 seconds. Physical attacks are AoE. TP use is doubled.
En-Light: Vulnerability Down on target for 10 seconds. Boosts targets-target defence by 20% for 20 seconds.
En-Water: Dropsy DoT. HP Regen for 15 seconds.
En-Air: Skill Speed up for 30 seconds. TP use is lowered
En-Dark: Vulnerability Down on target for 10 seconds. Grants targets-target with Dread Spikes.
Spike – 160 second Cool Down. Physical attacks only.
Ice Spikes: Reduces damage taken by 15% and delivers an attack with a potency of 100.
Blaze Spikes: Delivers an attack with a potency of 200 if struck with physical attacks.
Holy Spikes: Delivers an attack with a potency of 50. Grants user with Refresh.
Water Spikes: Delivers an attack with a potency of 50. Grants user with Regen.
Air Spikes: Delivers an attack with a potency of 75. Boosts users attack speed.
Dread Spikes: Delivers an attack with a potency of 100. Converts 5% of physical damage dealt to user to HP.
1-2 = Ice
1-2-3 = Fire
1-3-2 = Light
4-5 = Water
4-5-6 = Air
4-6-5 = Dark