This is probably my favorite toon for medium to very large engagements. I made this him with three objectives in mind: (1) ultra high survivability (2) group utility (3) good damage. Given these requirements I narrowed my list of possible toons to a HA wearing fighter base who could achieve good hitpoints and moderate defense, and had a nuke. For all of these in one toon, you only have a few options IMO. For me, Dwarf was a necessity for the toughness skill. I considered Crusader, but the damage of a fighter base is quite limiting, especially on a Dwarf. The only option for me was Sentinel.

I'm at work, so this is from memory:

Brilliant Mind (I think it was BM, but possibly WA)
Clever (I took the runes necessary to raise my Int via in-game runes)

In-game apply +5/10/15/20/25/30/35/40 Int rune and a 40 Con rune. I currently have a 25 int and 25 con applied. I have a 40 int and am looking for a 30/35 int and 40 con. this is a pain in the ass, but necessary IMO.

Hammer 100% (focus hammer)
Block 95%
HA spike to taste (100-110ish trains)
Abjuration spike to taste (100-110ish trains)
Toughness spike to taste (100-110ish trains)
Bomb 40
Small aoe 40
Manna drain/snare 20-40 to taste
Aoe debuff 40
Power damage buff 40
Sentinel stacking sprint 1
Runecaster heal 1-20 to taste
Harden Armor 20
Consecraye weapon 0-20 to taste

As you can see you have to make some choices. Trains are very tight. In the end, with full boons and seige buffs you can hit about 8,000 hitpoints, 1700 defense, 75% physical resist, bomb for over 5,000 max after the debuff, small nuke for over 1k max after the debuff; all while wearing a charmed of power neck.

The best part of the toon is the sheer survivability. Get a friendly channie to toss you Flesh of Lead, sache into an enemy stack and go crazy. With any healing at all you can withstand focus fire from not only multiple toons, but multiple groups of toons.

My routine is, prestun/stunbreak if available, combat stance, hit both sprints, hit the 100% GM block buff, charge the stack. It seems to work well, and your Prelates will love you as they aoe for 1200. Add a holy -resist spire and someone will get hurt. The time you buy your group while the entire enemy army targets you is enough to change many battles for the better in my experience.

Gear is expensive. I go with Jade of genius rings and Charmed of power neck. Avatars hammer of vampyre. +10 dex 8 def gloves, +8 + resist everything else, except boots which are +8 windlords of course.

Again, I'm at work, so some of this 411 may be a tad off. GL to any who decide to try the toon. I certainly enjoy mine. He has avenged my Glass Archmage AOE channie many times, who is his namesake.