You could have gone 2H with similar, if not better DPS and mitigation, and drop that garbage Dreugh King Slayer set.

Bonuses and Stats
The combo with Vicious Ophidian is a bad one since they give you the same bonus - Major Expedition when killing an enemy and those won't stack. Also if you aren using 2 Dreugh King on the body and 3 jewelry - that comes only in healthy - you are gimping yourself by ~2.5K stamina (3K+ if you include CP and possibly race multipliers). Note that Power of the Light scales on maximum stamina only, so you will lose big there. If you use it on the body you will lose 12% weapon damage from Medium Armor:Agility passive which means not only lower damage but lower healing as well since both Vigor and Repentance will scale on Weapon Damage and Maximum Stamina.

Skills
With One Hand and Shield you are also missing on a lot of damage from lack of spammable skills. Puncture damage is very low, and the only up side it gives is Major Fracture. Heroic Slash is also pretty low on damage which is only balanced by the utility it gives: Minor Heroism and snare, the latter being more important for PvP than PvE. The other skills are arguably either purely defensive - Absorb Magicka - or PvP only: Reverberating Bash (mobs in PvE don't heal themselves often and you can interrupt them anyway) and Invasion - with major expedition from Vicious Serpent you really don't need a gap closer and even if you do Critical Rush is arguably a better one.

Two Handed has:
- an execute: Reverse Slice, which also adds splash damage, especially if you weave it with heavy attack (Forceful and Follow up passives)
- a heal and Major Brutality all packed into one skill: Rally
- an AoE bleed and shield that scales with the number of enemies hitboth into one skill: Brawler
- a sustain passive that gives you extra stamina recovery when making a kill: Battle Rush
Also the weapon damage from equipping a 2H weapon is much higher than the 5% you get from 1H+S:Sword and board and the weapon damage on the equipped one had weapon

In practice
I've tried both in overland content and 2H makes you way "tankier" when tackling world bosses, as I've managed to beat them solo, with two notable exceptions: Zandaadunoz in Wrothgar due to the sheer number of adds that blow up and Vuyuvus in Vvardenfell due to the uninterruptible feed mechanic. With 1H+S you will just die slowly because you are unable to keep up the damage on target and sustain. Especially the lack of AoE damage is bad, since most of those world bosses come with hordes of adds (ex. Dubdil in Vvardenfell) and some of them come as a group (ex. Daedroth Larder in Coldharbour).

As a side node Dreugh King Slayer may work in PvP combined with a medium set like Bone Pirate Tatters if you chose to run 2W/Bow as the healthy jewelry will offset the lower health bonus from Dubious Camoran Throne, but in practice sets like Ravager will work much better if paired with crafted potions so no serious PvP-er would run Dreugh King Slayer instead of that. This set is one of the first I deconstructed to make room for better ones.

dreugh king slayer is a blast...

not only do you gain major brutality, but, the 2-3 set bonus gives you an extra 250 or so weapon damage, coupled with the warrior mundus and you actually can do a bit of damage with a more tanky type character...

yes, there are a bunch of different ways to gain major brutality, however - if they either don't apply to you based on class (templar), or you don't want to use the weapon or a skill which grants major brutality - very convenient set to use...

I've used it on my stamplar, stam blade and will use it on my stam warden when they reach 50...

I have no desire to use the bull netch or to use hidden blade (character is DW and bow)...

good way to diversify your build a bit...

heh stamplar tank with VO and repentence is fun in norm dungeons. mow down everything quickly, never run out of stamina, and leeroy jenkins ahead with speed buff.

The Warden one is probably even less populated, so you can basically Shalks-Netch-Bear-Broom-Bucket to the top 10, and you don't even need trash pots