At 50% difficulty mobs behave as normal, At 65% difficulty they reflect melee damage to the point that if I get a sneak attack off I will one shot myself. They do not appear to spell reflect or reflect poisons. This does not affect all mobs. specifically I noticed it applies to Clanifiears, Most Atrinarches, and some mobs related to the MQ. If anyone knows what mod causes this ridiculous amount of reflect damage I would appreciate a heads up so I can correct it.

Here is my load order:
Mart's Monster Mod.esm
Mart's Monster Mod for OOO.esm
Oblivion.esm
CM Partners.esm
ShieldOnBack.esm
MMM.esp
Nicos Gift.esp
DLCShiveringIsles.esp
Damage Text v2.esp
ShieldOnBack_1C.esp
Living Economy.esp
DMACArmor.esp
Sacredblade.esp
Silverlight Armor by Jojjo.esp
Warglaive - EV.esp
AncientTowers.esp
OOO-Armor_Perks_WearRate_Repair.esp
OOO-BirthSigns.esp
OOO-Combat_Skills_Perks_Marksmanship.esp
OOO-Dangerous_Traps.esp
OOO-Deadly_Combat.esp
OOO-Potions.esp
Nightshade_Armor.esp
adTreeHome.esp
BrotherhoodRenewed.esp
MountainTower.esp
xuldarkforest.esp
xulStendarrValley.esp
xulTheHeath.esp
XulEntiusGorge.esp
xulFallenleafEverglade.esp
xulColovianHighlands_EV.esp
xulChorrolHinterland.esp
mythsandlegends.esp
xulBeachesOfCyrodiilLostCoast.esp
xulBravilBarrowfields.esp
xulLushWoodlands.esp
xulAncientYews.esp
xulAncientRedwoods.esp
xulCloudtopMountains.esp
xulArriusCreek.esp
xulPatch_AY_AC.esp
xulRollingHills_EV.esp
xulPantherRiver.esp
xulRiverEthe.esp
xulBrenaRiverRavine.esp
xulImperialIsle.esp
xulBlackwoodForest.esp
xulCheydinhalFalls.esp
xulAspenWood.esp
xulSkingradOutskirts.esp
Stronger Soul Gems - no cap x3.esp
SupremeMagicka.esp
SM_ShiveringIsles.esp
SM_EnchantStaff.esp
SM_VanillaSpells.esp
SM_UnlockSpells.esp
SM_Scrolls.esp
SM_SigilStone.esp
MidasSpells.esp
Advanced Magecraft.esp
RshAlchemy.esp
StealthOverhaul.esp
Enhanced Mercantile Progress.esp
GalerionLeveling-v11.esp
DMC Stylish - Specialanims.esp
CM Partners.esp
CM Partners Special NPCs.esp
CM Partners NPC.esp
CM Partners More NPCs.esp
CM Partners Marker NPCs.esp
CM Partners Extra NPCs.esp
Aliyah.esp
CleanQuit.esp
Streamline 3.1.esp
Alittlegift.esp
Oscuro's_Oblivion_Overhaul.esp
_Ren_BeautyPack_full.esp
Knights.esp
Nicoroshi Creations DW Light.esp
ScarletMonastery.esp
Shadowcrest_Vineyard.esp
Mart's Monster Mod - Additional Enemy NPC Vars.esp
Mart's Monster Mod - City Defences.esp
Mart's Monster Mod - Diverse Creature Skins.esp
Mart's Monster Mod - Diverse Imperial Armor.esp
Mart's Monster Mod - Durability & Damage.esp
Mart's Monster Mod - Extra Wounding.esp
Mart's Monster Mod - Foxes.esp
Mart's Monster Mod - Hunting & Crafting.esp
Mart's Monster Mod - Less Rats.esp
Mart's Monster Mod - Looting NPCs & Creatures.esp
Mart's Monster Mod - More Wilderness Life.esp
Mart's Monster Mod - Resized Races.esp
Mart's Monster Mod - Spawn Rates - Moderate Increased.esp
Mart's Monster Mod - Vindasel.esp
Mart's Monster Mod for OOO.esp
ShadowfangKeep.esp
Display Stats.esp
Warglaives by Jojjo v1.0.SoB.esp
Thor'dal.esp

Other then not being sure what your saying, I know why at least Clanfear's and most Antro... Golems have reflect damage.
Because they have it in vanilla.

Other then these foes, I can't say why they might have reflect damage. Oh, and Poison can not be reflected, and spells are reflected by a different effect(one that is thankfully not seen on many monsters).

Another thing to note: Reflect Damage reflects a percent of your attack's damage. So, having a weapon that deals lots of damage when fighting clanfears is a bad idea, even more so if you have low health or are undetected, sneaking, and using a melee attack.
One of the big problems people making god weapons seem to not notice, really.

Also, your load order is either really f--ed up, or you typed it in yourself.

Lots of your mods require OOO, and you don't seem to have a ESM file of it. Oblivion.esm needs to be loaded first, no matter what.

I could say something about BOSS and why you should run it, but I'll leave that for people who actually use it.

Yes I don't really get what you mean about the whole mob reflect damage thing but YX33A is right (if a little harsh! lol). Your LO looks messed up.

1) From the look of your set-up you were going for a MMMforOOO install, right? if so use this: http://sites.google.com/site/oblivionpoinfo/walkthroughs/mmmooo & start again.

EDIT: ahh MMMforOOO.esm is the OOO.esm renamed ( i think) sorry! disregard above!

2) Get http://www.gamesas.com/index.php?/topic/1096264-boss-better-oblivion-sorting-software/ (orders your LO automatically & gives bashed patch suggestions) & http://www.gamesas.com/index.php?/topic/1098740-relz-wrye-bash-thread-45/ (you really need this even if only for the bashed patch)


You'll find this whole site useful if you read through it......http://sites.google.com/site/oblivionpoinfo/

What's already said. It's not caused by a mod but rather how the game works. At 100 difficulty reflect damage is extremely difficult to deal with - basically you need high alchemy skill and a bunch of restore health potions to manage it. Not sure if there's a mod dealing with this - I think it would be quite hard to implement.