I'm all for unicorn in everything lol.
I think for tank and counter damage having a good heal and decent matk are essential. I'd probably use:
Weapons:
Xtals: Unicorn, Gerust (Adds one sec skill delay suck for buffing), Sofys (If wep doesn't have autoskill already)
- Resty Rod: for matk buff on defense
- Dinat Rod: for +11% matk and matk up with vit
Armour
Xtals: Moldus/Unicorn/Sofys/Hp+20%
- Cleric Robe: for light counter and heal bonus
- Litch Armour: for mdef and def bonus (No counter)
- Dark priest robe: for dark counter attack and matk
- Iron Armour up: for more hp (No counter)
Additional:
Xtals: Unicorn/Hp 20%
- Viola: For counter attack and heal bonus
- Medic pouch: for heal bonus with cleric robe
- Gluck: for mp conservation
- Mercure - for matk, skill delay, and mp consumption
Special:
Xtals: Mezzaluna/Unicorn/Hp 20%
- Battery: for mp recovery
- Brave Bangle: for free slot
- Jar of Greed - Because...
I hear rumors of a sword that works like resty... its intriguing but I don't know anything about it or where to get it. I think the easiest way to solo level these characters will be a slow counter attack tank build. Mostly because you can control aggro and because you have instant heal and stone skin buff. If using buffs though you may need to get quick cool star abilities since we are focusing on equips that add survival and damage. As much as I love autoskill builds, like I did with my sword bishop, its really slow without a bishop, and counter more so because theres a lack of counter matk. For xtals theirs really only annubits and sofys, and I believe a event one also? Most people will mix offensive with defensive, but again its gunna be awesome with enchanter, not so much solo and it takes more points to go offensive also. I think tank will be best bet. Plus when you soul connect you get a bonus to hp so you further the benefits of high def and mdef by being a strong tank =3