skill mob rate not working properly

[testconta]

I would like to set up a mob to instantly use skill as an example Asura strike when getting close to any player. I tried to configure it but even though the rate is 100% it takes a LOT of time for the asura strike to come out.

1001,Scorpion@MO_EXTREMITYFIST,attack,271,5,10000,500,20,no,target,always,0,,,,,,18,

1001,Scorpion@MO_EXTREMITYFIST,chase,271,5,10000,500,20,no,target,always,0,,,,,,18,
1001,Scorpion@MO_EXTREMITYFIST,idle,271,5,10000,500,20,no,target,always,0,,,,,,18,
1001,Scorpion@MO_EXTREMITYFIST,attack,271,5,10000,500,20,no,target,always,0,,,,,,18,

 

[AnnieRuru]

{
Id: 1001
SpriteName: "SCORPION"
Name: "Scorpion"
Lv: 16
Hp: 153
Sp: 1
Exp: 108
JExp: 81
AttackRange: 1
Attack: [33, 7]
Def: 16
Mdef: 5
Stats: {
Str: 12
Agi: 15
Vit: 10
Int: 5
Dex: 19
Luk: 5
}
ViewRange: 10
ChaseRange: 12
Size: "Size_Small"
Race: "RC_Insect"
Element: ("Ele_Fire", 1)
Mode: {
CanMove: true
CastSensorIdle: true
CanAttack: true
Detector: true
ChangeTargetMelee: true
ChangeTargetChase: true
}
MoveSpeed: 200
AttackDelay: 1
AttackMotion: 1
DamageMotion: 1
MvpExp: 0
Drops: {
Boody_Red: 70
Scorpions_Tail: 5500
Elunium_Stone: 57
Solid_Shell: 210
Fine_Grit: 100
Yellow_Herb: 200
Lusty_Iron: 20
Scorpion_Card: 1
}
},

	SCORPION: {
		NPC_FIREATTACK: {
			SkillState: "MSS_BERSERK"
			SkillLevel: 1
			Rate: 2000
			Delay: 5000
			Cancelable: true
			SkillTarget: "MST_TARGET"
			CastCondition: "MSC_ALWAYS"
		}
		NPC_POISON: {
			SkillState: "MSS_BERSERK"
			SkillLevel: 1
			Rate: 500
			CastTime: 800
			Delay: 5000
			SkillTarget: "MST_TARGET"
			CastCondition: "MSC_ALWAYS"
		}
		NPC_POISONATTACK: {
			SkillState: "MSS_BERSERK"
			SkillLevel: 1
			Rate: 500
			CastTime: 300
			Delay: 5000
			SkillTarget: "MST_TARGET"
			CastCondition: "MSC_ALWAYS"
		}
		MO_EXTREMITYFIST: {
			SkillState: "MSS_ANY"
			SkillLevel: 5
			Rate: 10000
			CastTime: 0
			Delay: 0
			SkillTarget: "MST_TARGET"
			CastCondition: "MSC_ALWAYS"
		}
	}

you also need to lower monster's AttackDelay and AttackMotion for the monster to cast skill faster too