So here is my guy. I figured I would take an unorthodox approach and as such there are still aspects of him that need to be polished (equipment & AC being big ones) but his tactic should be good enough.
The Plague"We're not here because we're free; we're here because we're not free. There's no escaping reason, no denying purpose, because as we both know, without purpose, we would not exist. It is purpose that created us. Purpose that connects us. Purpose that pulls us. That guide us. That drive us. It is purpose that defines. Purpose that binds us. We're here because of you. We're here to take from you what you tried to take from us: purpose."[spoiler]
Male Exiled Modron, 3rd-Level Fangshields Ranger/1st-Level Wilderness & Martial Drow Rogue/4th-level Crusader/2nd-Level BloodHound/9th-Level Soul Eater Size/Type: Medium Living Construct
Hit Dice: 12d8+3/1d6+3/7d10+3 (170 hp)
Initiative: +1
Speed: 30 ft. (6 squares),
Armor Class: 13 (+0 armor, +1 Dex, +2 natural armor), touch 11, flat-footed 12
Base Attack/Grapple: +19/+23
Attack:
Unarmed Strike +24/+19/+14/+9 (3d6+4+2 negative levels/x2) or
Hand Crossbow +20/+15/+10/+5 (1d4/19-20x2; 30ft.)
Space/Reach: 5 ft./5 ft.
Special Attacks: Furious Counterstrike, Ready & Waiting, Soul Blast (9d6; 100ft.; Force; Reflex DC 19; 1/day),
Special Qualities: Living Construct traits, Vulnerability to Surprises, Favored Enemy (Arcanists +1), Voice of the City (+3), Poison Use, Steely Resolve 5, Mark (1), Non-Lethal Force, Indomitable Soul, Zealous Surge (1/day), Energy Drain (Negative Levels), Soul Strength, Soul Enchantment, Soul Radiance, Soul Agility, Soul Slave
Resistances: Immunity to poison, sleep, paralysis, disease, nausea, fatigue, exhaustion, sickening, & energy drain; Does not eat, sleep or breath; Acid Resistance 2, Cold Resistance 2, Fire Resistance 2, Immunity to Mind-affecting effects & abilities
Maneuvers (IL 16; Readied 5 [3])Saves: Fort +19 (+16 base, +3 Con), Ref +16 (+15 base, +1 Dex), Will +6 (+8 Base, -2 Wis) (+2 on saves vs. illusion & mind-affecting effects) (+10 bonus; 1/Minute)
Abilities: Str 18, Dex 12, Con 16, Int 18, Wis 6, Cha 10
Skills: Balance +14 (13 ranks, +1 Dex), Gather Information +9 (9 ranks, +0 Cha), Intimidate +26 (23 rank, +0 Cha, +3 deformity bonus), Jump +27 (23 ranks, +4 Str), Knowledge (Arcane) +5 (2 ranks, +3 Int), Knowledge (History) +6 (2 ranks, +4 Int), Listen +22 (22 ranks, -2 Wis, +2 racial), Move Silently +23 (22 ranks, +1 Dex), Search +25 (22 ranks, +3 Int), Spot +22 (22 ranks, -2 Wis, +2 racial), Survival +8 (10 ranks, -2 Wis), Tumble +20 (19 ranks, +1 Dex) and Use Rope +5 (4 rank, +1 Dex)
Feats: Improved Unarmed Strike [1st], Alertness [Flaw], Weapon Focus (Unarmed Strike) [Flaw], Track [Ranger1], Hand Crossbow Focus [Rogue1], Improved Natural Attack (Unarmed Strike) [Ranger2], Quick Draw [3rd], Endurance [Ranger3], Supreme Unarmed Attack [6th], Willing Deformity [9th], Deformity (Madness) [12th], Stand Still [15th], Extra Granted Maneuver [18th]
Possessions: Masterwork Hand Crossbow, Goggles (under a persistent Protection from Arrows spell) & a Courtier's Outfit (under a persistent Nondetection spell).
Alignment: Lawfully Evil
Languages: Abyssal, Common, Celestial and Infernal
Challenge Rating: 20[/spoiler]
So how does this little guy beat the near destructible mage? Attrition. Soul Eater's 9th-level ability Soul Slave transforms any creature destroyed by the Soul Eater into a wright (who themselves can continue this practice), but there happens to be no limit to how many wrights a Soul Eater may possess. So it is easy to say that The Plague will have, over a long time transformed every humanoid on his plane into a wright by mere attrition or killed them if not possible. He would have started with the small towns and worked his way up but sooner or later it would have happened. Then he would have transported from his plane to another and continued the process.
So what does this leave? The mage has to stay on his plane as there is nothing else for him out there. Want to maybe pick up a meal on the material plane? Nope, none there... The mage is also locked into submission as every single humanoid being in existence will have, over time, been transformed or killed by the mass of wrights.
So does this work?