[Norfleet]

The most important aspect of an SC is not his raw ability to kill things necessarily, but his ability not to get killed. Because it doesn't matter how hard you hit if you don't Last long enough to do any pummelling.

Several methods exist towards the "not being killed" angle: The first is to stack on protective magics and innate defenses like ethereal, lucky, mirror image, mistform, astral shield, etc. The second is to have very high values of protection, defense, and hitpoints. The third is to recover from damage faster than you can take it: regeneration and lifesteal. By combining all 3 of these elements together, you get something that just won't die easily.

Then, you need endurance: Your prospective SC is useless if he ends up nose down in the dirt from fatigue before he can complete his killing spree and people put him down like a dog. This can be accomplished through either high levels of reinvigoration, being 0-encumberance, or lifesteal.

Lastly, you need to be able to kill stuff. This means you need preferrably a modest value of attack, and probably some damage shields, or your ability to inflict carnage will cap out and you will lose battles from expiration: For weak swarmers, Fire Shield is good. Breath of Winter excellent also, as is Soul Vortex, which also provides lifesteal at the same time it hurts things. The pain inflicted by Soul Vortex is not really that much, however, so don't count on this as a hardcore damage shield. SV is also fairly high-tech, requiring Alt-6, so won't be available to you too early. Ability to move and attack twice a round via quickness is good, too.

Therefore, the components of a good SC: Many magical defenses, high defense and protection, low or no encumberance, lifesteal, regeneration, and high MR.

Examples:
Vampire Queen: naked: Quickness, Mirror, Mistform, Ironskin, Breath of Winter, attack
Ice Devil: blood thorn, lucky coin, starshine, robe of shadows, AMA, regen ring, flying shoes: Quickness, BoW, Attack
Niefel Jarl: Hellsword, Starshine, Hydra Skin, AMA, Lucky Pendant, Flying Shoes.
Bane Lord: Wraith Sword, Jade Armor, Starshine, AMA, Pendant, Flying Shoes: Attack.

These all of varying degrees of availability and strength, but all have a good selection of the above traits.

The Shedu, in my opinion, falls short because his primary attack form is trampling, which means he will fatigue out after about 10-15 tramples under the best of conditions. While his spell buffs can be tolerable enough to keep him alive, and he has many hitpoints, this isn't enough to save him once he passes out....and he will pass out. You can alleviate this problem of a Shedu or similar chassis becoming overwhelmed by accompanying him with troops, but he's no longer able to simple go on solo rampages through the countryside, mowing down entire armies unassisted, which is what SCs do. Thus, Shedu are bad SCs.