Need Help with Royal Guard build

[Joelle]

I've always been a magic class user (my Arch Bishop one of the leaders in PvP on my server - but I've always wanted to try a tank job, more specific Royal guard.)  Problem is, I know nothing about the melee classes and need some help on the build - I'm leaning toward Devo more so than Sac.

The stats for our server (Rare RO)  is 255/120 with 3rd job; insta cast is DEX 180 and max stats is 255 - I'm un-statted right now since I'm not familiar

My gear is as follows:

+7 Valk set (armor, shoes and mant)
+8 Imperial Shield
+0 Gold Dragon Helm (Increases Maximum SP and Maximum HP by 13% Hit rate + 15% Vit + 10) - upper
+0 Rose Ring (Increases Maximum SP and Maximum HP by 13% Hit rate + 15% Vit + 10) - mid
+0 Rare Gear Wing (Allstats + 10 HP + 12% Atk + 10% Matk + 10% Vit Based Def - 7 Resistant to Water 15% Resistant to Fire 15%) - lower
Diablos Ring and Bradium Ring in the Accessory slots

Weapons: +10 Elemental Sword (2TGc + Hydra) and +10 Pike (2TGc + Thana + Hydra)

I'm holding onto a Tao Gunka and Orc Hero in my inventory

Please help