Nahlea

That your problem you have to add that to the powers behaviors. Sorry that i didn't mention that i thought you would have done that already.

You shouldn't be sorry for things you didn't knew

I am glad you tried to help me, which is a sign of character, so thanks anyway.

Then add it to the Experience Levels.

Did that as well and still no good result :(
I might be doing something wrong (without a doubt:P)

Let me show you what i got so far:

Individual file for the balrog (not pasting code to prevent wall of text)

Comandbutton.ini

CommandButton Command_SpecialAbilityIgnite
  Command				 	= SPECIAL_POWER 
  SpecialPower				= SpecialAbilityHeroMode
;  Options				 	= 
  TextLabel			   	= CONTROLBAR:SpecialAbilityIgnite
  ButtonImage			 	= HSBalrogIgnite
  ButtonBorderType			= ACTION 
  DescriptLabel		   	= CONTROLBAR:ToolTipSpecialAbilityIgnite	 	
  InPalantir			= Yes
End

CommandButton Command_SpecialAbilityFireWhip
  Command				 	= FIRE_WEAPON 
  WeaponSlot				  = SECONDARY
  Options				 	= NEED_TARGET_ENEMY_OBJECT
  TextLabel			   	= CONTROLBAR:SpecialAbilityFireWhip
  ButtonImage			 	= HSBalrogFireWhip
  ButtonBorderType			= ACTION 
  DescriptLabel		   	= CONTROLBAR:ToolTipSpecialAbilityFireWhip
  CursorName				  = EvilAbilityObj
  InvalidCursorName	   	= GenericInvalid
;  UnitSpecificSound	   	= 
  InPalantir			  = Yes
End

CommandButton Command_SpecialAbilityBalrogBreath
  Command				 = SPECIAL_POWER 
  SpecialPower			= SpecialAbilityBalrogBreath
  Options				 = NEED_TARGET_POS CONTEXTMODE_COMMAND
  TextLabel			   = CONTROLBAR:SpecialAbilityBalrogBreath
  ButtonImage			 = HSBalrogBreathFire
  ButtonBorderType		= ACTION 
  RadiusCursorType		= FireBreathRadiusCursor   
  DescriptLabel		   = CONTROLBAR:ToolTipSpecialAbilityBalrogBreath
;  UnitSpecificSound	   	= 
  InPalantir			= Yes
End

CommandButton Command_SpecialAbilityBalrogWings
  Command				 	= SPECIAL_POWER 
  SpecialPower				= SpecialAbilityBalrogWings
  Options				 	= NEED_TARGET_POS CONTEXTMODE_COMMAND
  TextLabel			   	= CONTROLBAR:SpecialAbilityBalrogWings
  ButtonImage			 	= HSBalrogWings
  ButtonBorderType			= ACTION 
  CursorName			= EvilAbilityObj  
  InvalidCursorName		  = GenericInvalid
  DescriptLabel		   	= CONTROLBAR:ToolTipSpecialAbilityBalrogWings
;  UnitSpecificSound	   	= 
  InPalantir			= Yes
End

Comandset.ini

CommandSet BalrogMPCommandSet
	1	  = Command_ToggleStance
	2	  = Command_SpecialAbilityBalrogWings
	3	  = Command_SpecialAbilityIgnite
	4	  = Command_SpecialAbilityFireWhip
	5	  = Command_SpecialAbilityBalrogScream
	6	  = Command_SpecialAbilityBalrogBreath
	13 	= Command_AttackMove
	14 	= Command_Stop
	16	  = Command_SetStanceBattle
	17	  = Command_SetStanceAggressive
	18	  = Command_SetStanceHoldGround
End

Upgrade.ini

Upgrade Upgrade_BalrogWings
	Type			= OBJECT
End

Upgrade Upgrade_SpecialAbilityIgnite
	Type			= OBJECT
End

Upgrade Upgrade_FireWhip
	Type			= OBJECT
End

Upgrade Upgrade_BalrogScream
	Type			= OBJECT
End

Upgrade Upgrade_BalrogBreath
	Type			= OBJECT
End

Experiencelevel.ini

ExperienceLevel	BalrogMPLevel1
	TargetNames						=	BalrogMP
	RequiredExperience				=	1	
	ExperienceAward					=	BALROG_MP_LVL1_EXP_AWARD
	Rank							=	1
	Upgrades						=	Upgrade_BalrogWings
	SelectionDecal
		Texture						=	decal_hero_good	
		Style						=	SHADOW_ALPHA_DECAL
		OpacityMin					=	50%	
		OpacityMax					=	100%
		MinRadius					=	40;16
		MaxRadius					=	200;16
		MaxSelectedUnits			=	40;1
	End	
End	

ExperienceLevel	BalrogMP2
	TargetNames						=	BalrogMP
	RequiredExperience				=	BALROG_MP_LVL2_EXP_NEEDED 
	ExperienceAward					=	BALROG_MP_LVL2_EXP_AWARD
	AttributeModifiers				=	HeroLevelUpDamage1
	Rank							=	2
	Upgrades						=	Upgrade_SpecialAbilityIgniteMP
	LevelUpFx						=	FX:GandalfLevelUp1FX
;LevelUpOCL						=	OCL_GandalfLevelUp1OCL
	SelectionDecal
		Texture						=	decal_hero_good	
		Style						=	SHADOW_ALPHA_DECAL
		OpacityMin					=	50%	
		OpacityMax					=	100%
		MinRadius					=	40;16
		MaxRadius					=	200;16
		MaxSelectedUnits			=	40;1
	End	
END	

ExperienceLevel	BalrogMPLevel3
	TargetNames						=	BalrogMP
	RequiredExperience				=	BALROG_MP_LVL3_EXP_NEEDED 
	ExperienceAward					=	BALROG_MP_LVL3_EXP_AWARD	
	AttributeModifiers				=	HeroLevelUpDamage2
	Rank							=	3
	Upgrades						=	
	LevelUpFx						=	FX:GandalfLevelUp1FX
;LevelUpOCL						=	OCL_GandalfLevelUp1OCL
	SelectionDecal
		Texture						=	decal_hero_good	
		Style						=	SHADOW_ALPHA_DECAL
		OpacityMin					=	50%	
		OpacityMax					=	100%
		MinRadius					=	40;16
		MaxRadius					=	200;16
		MaxSelectedUnits			=	40;1
	End	
END	

ExperienceLevel	BalrogMPLevel4
	TargetNames						=	BalrogMP
	RequiredExperience				=	BALROG_MP_LVL4_EXP_NEEDED 
	ExperienceAward					=	BALROG_MP_LVL4_EXP_AWARD	
	AttributeModifiers				=	HeroLevelUpDamage3
	Rank							=	4
	Upgrades						=	
	LevelUpFx						=	FX:GandalfLevelUp1FX
;LevelUpOCL						=	OCL_GandalfLevelUp1OCL
	SelectionDecal
		Texture						=	decal_hero_good	
		Style						=	SHADOW_ALPHA_DECAL
		OpacityMin					=	50%	
		OpacityMax					=	100%
		MinRadius					=	40;16
		MaxRadius					=	200;16
		MaxSelectedUnits			=	40;1
	End	
END

etc (not pasting everything to keep thing compact)

Edit:
Atm i am going to try an add a new behavior with "TriggeredBy = Upgrade_<skill name>"

You have to make upgrades in the upgrade.ini for his powers(skills).

I have made the upgrade, but the result is the same, which means all the powers of the balrog are avaible from the start.

You didn't have to replace a unit you could of just made a new command button and added it to the command set of the barracks.

Yea i noticed that as well , but thanks for telling me anyway, much appreciated

Try replacing the current hero respawn commandbuttons in the Fortress commandsets with normal unit recruit ones that recruit your hero instead (style them after, say, the MotW Trebuchet would be good).

I got it to work by replacing the spearman in the barracks with a hero. Thanks.