Unbroken/Trickster with Whisper of the Endless Paths. Also works als Devoted/Trickster if you don't want to focus too much on your disengagement bonuses but want better PEN in general. Depends on how you want to play this.
The main idea:
Be a tanky guy but dish out a lot of damage via retaliation
Whispers of the Endless Paths: Offensive Parry. Triggers on every miss.
Riposte (stacks with Offensive Parry)
Defender Stance + Hold the Line + Persistent Distraction: unlock Deathblows on lots of enemies passively or
Mob Stance if you don't need to hold a lot of engagement. You can also switch for more flexibility.
Either Patinated Plate (max armor option) or
Nomad's Brigandine (+deflection and good AR - good mix) or
Casita Samelia's Legacy Breastplate (medium armor but great deflection via Intimidate, can retaliate as well, also comes rel. early) or
Gipon Prudensco (variant with lightest AR and focus on leaving engagement on purpose in order to trigger disengagment attacks with ultra high deflection bonus which then get reflected - leading to crazy dps - but risky due to low AR)
One Dozen Stood Plate (focus on terrify + forcing enemies to disengage)
later Champion's Helm (more riposte) or Mask of the Weyc (nice deflection boost of +50 at the start of battle)
crank your deflection as high as you can (max RES, Entonia Signet, Cloak of Greater Deflection, Bracers oGD, Superior Deflection, Refrshing Defense, Mirrored Images also Escape which lasts quite some time with highest INT and +1 PL and so on...)
max INT and Tactical Barrage for longer durations, bigger cone and +1 PL
standard MIG, CON, DEX, bit higher PER. You can also lower DEX and put more in MIG
Use Repulsive Visage with Defender Stance and Overbearing Guard: enemies will get terrified and will break engagement: you attack with mighty PEN and dmg bonus and knock them prone.
Your team members should help you with abilites which lower the accuracy of the enemies (Chillfog, Miasma, Devotions otF, Disponent Blows). Thisall produces more misses on the enemies' side.
You can play this stationary (heavy armor) or with a lot of running around (triggering disengagement attacks). I presume you like the first one better.
This can be you main tank if you also bring a large shield + modal. Switch to that if you get shot a lot/cast at a lot and things don't go like you planned. This build is great against all sorts of melee attackers but not perticularly good against ranged and casters. So I play him in a front line of three (all three not full tanks).
Here's a small test session with the Casita-variant:
small video