Assassin/Ninja Help Grimtrap

I wan't to be able to solo Bosses such as wybel and qira c:

I wanna do enough damage while being some kind tanky

 

Shawl of Gaea
Taurus
Greaves of Veneer
Gaea-Hewn Boots / Scorpio

Tisaun's Honour
Concentration
Squid Anklet
Royal Dusty Amulet

Skill points: 90 Str, 0 Dex, 40 Int, 70 Def, and 0 Agi.

You'll need Grimtrap (obviously) and Big Arms to solo Qira since Earth is not effective on Qira, though spells are impeded. You can use Grimtrap as the spell / poison weapon, and Wall Breaker as a melee weapon. Big Arms can be used as the neutral melee damage.