Alright, long post coming up.
I've done the basic 20 level mock-up of what I would like to do with the character, barring any bounses from the Kensai Signature Weapon feature (since I don't quite know what to expect from it with natural weapons) and this is what I came up with.
* denotes feats that my DM has approved to retrain due to Class feature overlap at later levels. I've tried to maintain balance by retraining a feat into another feat that is related to the previous feat. [I.E. Improved Unarmed Strike retrains to Weapon Focus (Unarmed Strike)]
** denotes bonus feats that have been granted Exalted status due to DM ruling that only after gaining all other applicable Exalted bonus feats, I could dip into normal feats for Vow of Poverty bonus feats.
Armor Class in our campaign is determined by rolling d20 and adding modifiers. AC should be read as +DEX +Monk AC bonus-if any (+VoP AC bonus)(+deflection bonus-if any)(+Natural armor bonus-if any)(+dodge bonus-if any)
Attack Bonus should be read as +Base (+WIS mod)(+Exalted Strike)(+proficency bonus)
Race: Human
Class: Fighter 4/Monk 6/Kensai 10 ECL: 20
Stats: [Base/Lvl mod (+ability bonuses)]
STR: 17/+1 (+4)
DEX: 17/+1 (+6)
CON: 17/+1 (+2)
INT: 16
WIS: 18/+2 (+8)
CHA: 17
Lv1: Human: Sacred Vow; Lv1: Vow of Poverty; Ftr1: Combat Expertise; VoP1: AC+4, Intuitive Attack
Lv2: Ftr2: Improved Trip; VoP2: Touch of Golden Ice
Lv3: Lv3: Dodge; VoP3: AC+5, Endure Elements
(Campaign start) Lv4: +1 DEX; Ftr4: Improved Unarmed Strike; VoP4: Exalted Strike +1(magic), Sanctified Natural Attack
AC: +4(+5)(+1) AB: +4(+4)(+1) Saves: +4, +1, +1 Dmg: d3+1(magic)
Lv5: Mnk1: Improved Unarmed Strike, Flurry (-2), Monk AC, Stunning Fist; Retrain Ftr 4: Weapon Focus (Unarmed)*; VoP5: Sustenance
AC:+4+4(+5)(+1) AB: +4(+4)(+1)(+1) Svs: +6, +3, +3 Dmg: d6+1 (magic)
Lv6: Mnk2: Evasion, Combat Reflexes; Lv6: Defensive Throw; VoP6: AC+6, Deflection +1, Nymph's Kiss
AC: +4+4(+6)(+1)(+1) AB: +5(+4)(+1)(+1) Svs: +7, +4, +4 Dmg: d6+1 (magic)
Lv7: Mnk3: Still Mind, Fast Movement +10; VoP7: Wis+2, Resistance +1
AC: +4+5(+6)(+1)(+1) AB: +6/+1(+5)(+1)(+1) Svs: +8, +5, +5 Dmg: d6+1 (magic)
Lv8: +1 STR; Ken1: Signature weapon (Unarmed-fists), Monk cross-class; VoP8: Natural Armor +1, Mind Shielding, Servant of the Heavens
AC: +4+5(+6)(+1)(+1)(+1) AB: +6/+1(+5)(+1)(+1) Svs: +8, +5, +7 Dmg: d6 +1 (magic)
Lv9: Ken2: Power Surge; Lv9: Hold the Line; VoP9: AC+7
AC: +4+5(+7)(+1)(+1)(+1) AB: +7/+2(+5)(+1)(+1) Svs: +8, +5, +8 Dmg: d6 +1 (magic)
Lv10: Ken3; VoP 10: Exalted Strike +2(good), DR 5/magic, Nimbus of Light
AC: +4+5(+7)(+1)(+1)(+1) AB: +8/+3(+5)(+2)(+1) Svs: +9, +6, +9 Dmg: d6 +2 (magic/good)
Lv11: Ken4: Ki Projection (1/2); VoP 11: Wis+4, Dex+2
AC: +5+6(+7)(+1)(+1)(+1) AB: +9/+4(+6)(+2)(+1) Svs: +9, +6, +10 Dmg: d6 +2 (magic/good)
Lv12: +1 Con; Ken5: Withstand; Lv12: Improved Natural Attack; VoP12: AC+8, Deflect +2, Greater Sustenance, Holy Radiance
AC: +5+6(+8)(+2)(+1)(+1) AB: +9/+4(+6)(+2)(+1) Svs: +9, +6, +10 Dmg: d8 +2 (magic/good)
Lv13: Mnk4: Ki Strike (magic), Slowfall (20ft), Flurry (-1); VoP13: Resistance +2, Energy Resistance 5 (acid, cold, electricity, fire, sonic)
AC: +5+6(+8)(+2)(+1)(+1) AB: +10/+5(+6)(+2)(+1) Svs: +11, +8, +12 Dmg: 2d6 +2 (magic/good)
Lv14: Ken6; VoP14: Exalted Strike +3, Freedom of Movement, Stigmata
AC: +5+6(+8)(+2)(+1)(+1) AB: +11/+6/+1(+6)(+3)(+1) Svs: +12, +9, +13 Dmg: 2d6 +3 (magic/good)
Lv15: Mnk5: AC bonus +1, Purity of Body; Lv15: Superior Unarmed Strike; VoP15: AC+9, DR 5/evil, Wis+6, Dex+4, Str+2
AC: +6+8(+9)(+2)(+2)(+1) AB: +11/+6/+1(+7)(+3)(+1) Svs: +12, +9, +13 Dmg: 2d8 +3 (magic/good)
Lv16: +1 Wis; Ken7; VoP16: Natural Armor +2, Gift of Faith
AC: +6+8(+9)(+2)(+2)(+1) AB: +12/+7/+2(+7)(+3)(+1) Svs: +12, +9, +14 Dmg: 2d8 +3 (magic/good)
Lv17: Ken8: Ki Projection (full), Instill; VoP17: Exalted Strike +4, Resistance +3, Regeneration
AC: +6+8(+9)(+2)(+2)(+1) AB: +13/+8/+3(+7)(+4)(+1) Svs: +13, +10, +16 Dmg: 2d8 +4 (magic/good)
Lv18: Ken9; Lv18: Power Attack; VoP18: AC+10, Deflection +3, True Seeing, Exalted Improved Bull Rush**
AC: +6+8(+10)(+3)(+2)(+1) AB: +13/+8/+3(+7)(+4)(+1) Svs: +14, +11, +16 Dmg: 2d8 +4 (magic/good)
Lv19: Mnk6: Improved Trip, Slowfall (30ft), Fast movement +20; Retrain Ftr2: Cleave*; VoP19: DR 10/evil, Wis+8, Dex+6, Str+4, Con+2
AC: +7+9(+10)(+3)(+2)(+1) AB: +14/+9/+4(+8)(+4)(+1) Svs: +15, +12, +17 Dmg: 2d8 +4 (magic/good)
Lv20: +1 Wis; Ken10: Ki Warlord; VoP20: Exalted Strike +5, Energy Resistance 15 (acid, cold, electricity, fire, sonic), Exalted Great Cleave**
AC: +7+10(+10)(+3)(+2)(+1) AB: +15/+10/+5(+9)(+5)(+1) Svs: +15, +12, +18 Dmg: 2d8 +5 (magic/good)
So, what do you think?