Hahah, I remembered posting about monk here, but didn't recall that being so similar xD I repeated history, hah.
As for the god build... It depends on the magic level. Monk scales very well with magic level, since he gets ac from wisdom. So it's true he can become untouchable given enough magic (though everyone is untouchable with +20 items available, because AC scales much faster with items than AC). But it's known that dexterity builds get most ac, and even for the monk probably focusing on dex is better than wis - +ab is better than +stunning fist DC. Still the AC difference winds up to monk level-based AC bonus (8 maximum)+modifier from wis versus AC coming from shields (or level-based AC bonuses of dragon disciple/pale master/whoever else gets them).
For good monks there's of course intuitive attack (that really should be for any alignment...), but it is limited by the hardcoded +20 attack cap... Still great for caster monks, where WIS gets you AC, attack, bonus spells, spell DCs, stunning fist DC, damage if Sacred Fist... You turn MAD into SAD. Can be a little circumvented by having also a naturally high DEX/STR, because every point of DEX/STR mod means a smaller bonus from intuitive attack (i think its coded that way? That it gives the difference between ability mods as a bonus to attack?), but it requires weapon finesse if Dex is higher than STR.
Imo the god build might very well contain monk and then it would be something like monk/druid/sacred fist or maybe shadowdancer just for hips (or screw SD if your race has hips... Another factor-which races are allowed). Another option would be nymph epic divine might/shield shenanigans. A build like shaman/rdd/heartwarder has insane ac, saves, can get divine power and mantle of egregious might in a domain slot and is a full caster - sadly with a limited spell list. Could still go cleric (worse saves, better spells, but domains are restricted to protection, good and charm) or different divine caster (Archivist for ultimate spell list, Favored Soul for cha synergy - but still DCs based on wis, Druid seems a bad idea here) and forgo RDD for Hospitaler, or go Templar for ultimate cha synergy (but shitty spell list - no heal, no harm, no greater restoration, no implosion, no destruction, no drown, also no sanctified nor corrupt spells).
Since this is what just came out of the top of my head, it's probably shitty and can be easily defeated.
ToB classes can be pretty OP with spammable time stops, double whirlwinds, insane amounts of attacks using maneuvers like raging mongoose or time stands still, overcoming DR with Mountain Hammer line or Foehammer.
..And exploiting time stops with their maneuvers, since every time you time stop you paralyze your opponents, and then you can make an attack using a maneuver to coup de grace for 9999 damage ;P That's pretty godly
It still wouldn't work on constructs and undead though. But an ordinary monk? Eats dirt ;P