RO

Yamikumo
Consumption: 10 SP
Prereq: Kagekiri 5
MaxLv: 1
Hide one's presence. Basically, it's similar to Thief's Hide skill. SP is reduced by fixed amount while under this status. Either using it again, or reaching 0 SP will remove it.

Right Hand Mastery
MaxLv: 5 (Passive)
Recover the attack power lost from equipping two weapons.
(80% at Lv 1, maxes out at 120% at Lv 5)

Left Hand Mastery
MaxLv:5 (Passive)
Recover the attack power lost from equipping two weapons.
(60% at Lv 1, maxes out at 100% at Lv 5)

Juumonjigiri
Level Selectable
MaxLv: 5
Prereq: Yamikumo 1
Kagerou and Oboro's "Combination Attack" (Not sure if Oboro A x Oboro B and the like is possible; or if you can just do two Juumonjigiri by yourself)
While under Juumonjigiri state, if it is used again after a certain time, then it will do additional damage.
The higher the user's base lever, the higher the 'additional damage' will be.
(3 cell range at Lv 1, 7 cell range at Lv 5)
(150% attack at Lv 1, 750% attack at Lv 5)
(20 SP at Lv 1, 36 SP at Lv 5)

Tamashii Setsudan
Level Selectable
MaxLv: 5
Prereq: Juumonjigiri 2
If the target is under the Soul Linker's Spirit buffs, then you'll do additional damage to the target.
It will also forcibly remove the Spirit Buff from the target.
The higher the Spirit skill, the higher the additional damage will be.
(100% attack at Lv1, 500% at Lv 5)
(12 SP at Lv 1, 28 SP at Lv 5)
(Range is 2 regardless of Level)

Bakuretsu Kunai
Level Selectable
MaxLv: 5
Prereq: Kunai Nage 5
Throw a Kunai with explosive power, and deal damage to the target and it's surroundings.
Consumes 1 Explosive Kunai.
(7 cell range at Lv 1, and 11 cell range at Lv 5)
(5 SP at Lv 1, 9 SP at Lv 5)

Happo Kunai
Level Selectable
MaxLv: 5
Prereq: Bakuretsu Kunai
Damage all enemies within a certain "radius" (with yourself as center) using kunai.
Consumes 8 kunai.
(9x9 range with yourself as senter at Lv 1 to 4, 11x11 at Lv 5)
(12 SP at Lv 1, 20 SP at Lv 5)

Fuuma Shuriken Ranka
Level Selectable
MaxLv: 5
Prereq: Fuuma Shuriken Nage 5
Throw the fuuma shuriken, damage all enemies within the 7x7 cell range.
The user's AGE, DEX, and the level of the Ninja Skill Fuuma Shuriken Nage will increase the damage.
(150% attack at Lv 1, 750% attack at Lv 5)
(9 cell range at Lv 1, 13 cell range at Lv 5)
(24 SP at Lv 1, 40 SP at Lv 5)

Makibishi
Level Selectable
MaxLv5
Prereq: Zen Nage
Spread spiky tools (aka caltrops) on the surrounding ground. If an enemy steps on this, they'll be unable to move for a while and be stunned. Higher level of skill increases the number of spikes thrown, and be capable of using the skill while moving.
(3 spikes at Lv 1, 7 spikes at Lv 5)
(9 SP at Lv 1, 21 SP at Lv 5)
(Range is 7 regardless of level)

Mucha Nage
Level Selectable
MaxLv: 10
Consumes 50 SP
Prereq: Makibishi
Zen Nage's stronger version. Throw up to 100k zeny, and deal random damage the ignores defense.
Deals half damage to boss monsters.
(10k zeny at Lv 1, 100k zeny at Lv 10)
(11 cell range for all levels)
(damage dealt is randomly chosen from 50% to 100% of the zeny thrown)
(i.e. at Level 10, it deals damage randomly between 50k to 100k)

MeiKyouShiSui
Level Selectable
MaxLv: 5
SP Consumed: 100 (?)
Prereq: Ninja Mastery 10
For 10 seconds, focus your mind, and recover HP and SP at a extremely fast rate.
While using the skill, you will not be able to move.
If you are attacked while under this skill, there's a certain chance that you won't receive the damage
(2% HP per second at Lv 1, 10% HP per second at Lv 5) [That means 100% HP recovered after 10 seconds]
(1% SP per second at Lv 1, 5% SP per second at Lv 5) [That means 50% SP recovered after 10 seconds]

Zanzou
Level Selectable
MaxLv: 5
Prereq: Utsusemi 1 (cicada)
Create a bunshin that looks exactly like you. The bunshin you created has a fixed amount of HP, and disappears if it reaches 0 HP.
(3k HP at Lv 1, 10k HP at Lv 5)
(40 SP at Lv 1, 56 SP at Lv 5)

Kyougaku
Level Selectable
MaxLv: 5
Prereq: Genwaku 2
Cast genjutsu upon the target, and lowers all stat and changes his form into a monster.
Affected target will not be able to change equipment while the effect is still on-going
(5 cell range)
(5 to 10 stats reduction at Lv1, 25 to 50 stats reduction at Lv 5)
(40SP at Lv1, 56 SP at Lv 5)

Juusatsu
Level Selectable
MaxLv: 5
Prereq: Kyougaku
Cast genjutsu upon the target, and cast a curse (not sure if it's the old Curse status) on top of reducing HP.
There's a low chance to cause Coma. Coma won't affect if the target is the same level or higher than the user.

Genwaku
Level Selectable
MaxLv: 5
Switches position of user and target. There's a fixed chance that you or the target will be in Confusion.
(40 SP at Lv 1, 56 SP at Lv 5)
(5 cell range at Lv 1, 9 cell range at Lv 5)

Izayoi
Level Selectable
MaxLv: 5
Removes the fixed casting time and halves the variable casting time of all the skills that Ninja uses (Ninja only? Not Kagerou/Oboro?)
Also, increase MATK by a certain amount. SP is continually consumed while under this status.
(50 MATK at Lv 1, 250 MATK at Lv 50)
(70SP at Lv 1, 90 SP at Lv 5)

Enten/Fubuki/Seiran
MaxLv: 1
SP Consumed: 20
Use a Fire/Water/Wind Fuseki to summon a Fire/Water/Wind spirit, and increase the Fire/Water/Wind Ninpou's attack power.
Also, turns the user's weapon to Fire/Water/Wind element. Consumes 1 Fire/Water/Wind Fuseki per use.
You can have up to 10 Fuseki at a time.

Koukai
MaxLv: 1
SP Consumed: 20
Use a Earth Fuseki to summon a Earth, and increase the user's Attack Power and Defense Power.
Also, turns the user's weapon to Earth. Consumes 1 Earth Fuseki per use.
You can have up to 10 Fuseki at a time.

Jutsushiki Kaihou
MaxLv: 1
SP Consumed: 10
Prereq: Each of the Kagerou/Oboro elemental buffs
Unleash the spirit's power to deal damage to one target. Element is dependent on the summoned spirit.

Jutsushiki Zenkai
MaxLv: 1
SP Consumed: 30
Prereq: Jutsushiki Kaihou 1, Izayoi 1
Expand the power of spirits you possess into the ground and create formations that does multiple effects.
-Fire element spirit > Causes Burning to all enemies within range. Increase Attack Power if you're equiped with Fire-elemental weapon.
-Water element spirit > Causes Freezing, Frozen, or Cold to all enemies within range. Increase Attack Power if you're equiped with Water-elemental weapon.
-Wind element spirit > Causes Silence, Sleep, or Deep Sleep to all enemies within range. Increase Attack Power if you're equiped with Wind-elemental weapon.
-Earth element spirit > Causes Stone Curse or Poison to all enemies within range. Increase Attack Power if you're equiped with Earth-elemental weapon.

Kagefumi
Level Selectable
MaxLv: 5
Prereq: Zanzou 1
Stop all targets around you for a certain time, forcibly removes any skill that makes them unseen.
(5x5 range at Lv1, 13x13 range at Lv5)
(25 SP at Lv 1, 45 SP at Lv 5)

Kyomu no Kage
Level Selectable
MaxLv: 5
Consumed SP: 50(?)
Prereq: Kagefumi 2
For a certain time, nullify the targets' reflect skill.
If the enemy is charmed by Kyomu no Kage, there's a certain rate that their skills will fail.
Consumes 1 Shadow Ball per use.
(10 secs at Lv 1, 30 secs at Lv 5

Kagemusha
Level Selectable
MaxLv: 5
Prereq: Kyomu no Kage
Gives the skill Double Attack to the target for a certain amount of time.
The effect is removed if either the duration ends or you have received a certain amount of damage.
While under the effect, the target's SP will be reduced by 1 per second.
(60sec duration at Lv 1, 180 sec duration at Lv 5)
(60 SP at Lv 1, 80 SP at Lv 5)

Zangetsu
Level Selectable
MaxLv: 5
Prereq: Genwaku
Changes the target's ATK and MATK base on their level. Buff on allies, debuff on enemies. (According to RWC 2011 announcement anyways.)
(60sec duration at Lv 1, 120sec duration at Lv 5)
(60 SP consumed at Lv 1, 100 SP consumed at Lv 5)

Akaitsuki
Level Selectable
MaxLv: 5
Prereq: Zangetsu 2
If the affected target of this skill receives certain HP Recovery Skills, they will receive damage instead of HP recovery. This skill cannot be used on players outside PvP territories. It also can't be used on Boss Monsters.
(20SP at Lv 1, 60 SP at Lv 5)
(7 cell range regardless of level)

Oboro Gensou
Level Selectable
MaxLv: 5
Prereq: Akaitsuki 3
Randomly increase or decrease the target's HP and SP. If one is attacked by a magic attack while under this skill's effects, then that magic attacks's damage will distributed to those surrounding the target. Doesn't affect Boss Monsters.
(55 SP at Level 1, 75 SP at level 5)
(7 cell range regardless of level)