This is an AWESOME power, I love the theme of it. I really enjoyed digging into this one. Lets go!
FLOOD LAUNCH SPECIAL ATTACK
Range Special, Attack 4
After moving and instead of attacking normally, any unengaged Stormshell Warrior within 2 clear sight spaces of Majikobe may use Flood Launch. When using Flood Launch, choose 4 spaces in a straight line from the Stormshell Warrior. Move the Stormshell Warrior on the chosen spaces, up to 3 spaces, counting elevation normally. If the Stormshell Warrior ends their movement adjacent to an opponent's figure that is on a chosen space, roll 4 attack dice against that figure. While using Flood Launch, Stormshell Warriors do not take leaving engagement attacks. Flood Launch can only be used if Majikobe did not use Deadly Torrent Special Attack during the player's turn.
Firstly, its periods, not commas in the range and attack line, FYI.
For the first part of the text, I'm stealing wording from the Vulcanmech Incendiborg's Flamethrower Special Attack, adding in the stipulations for being unengaged and within clear sight of the hero. This wording allows some figures to attack normally and some to attack with this special attack. It is also shorter by cutting out some unnecessary phrasing and is more specific by referencing "the attacking" figure.
"An unengaged Stormshell Warrior within 3 clear sight spaces of Majikobe may use Flood Launch Special Attack. Choose 4 spaces in a straight line from the attacking Stormshell Warrior."
The next part you have is pretty good, except I'm rearranging the first sentence to be a bit more specific and you don't need to specify attack dice in the power unless it is variable (like Samuel Brown's Fire and Rush). Clarified, It looks like this.
"Move the attacking Stormshell Warrior up to 3 spaces along the chosen spaces. If the Stormshell Warrior ends their movement adjacent to an opponent's figure on a chosen space, attack that figure."
And then the caveats at the end of the power. The first is good. The second has to be reworked. Unfortunately, the rules do not differentiate between a "player turn" and a "figure turn" and so while your wording is specific enough to explain your meaning accurately, you're using a term that does not exist. And solving it is tricky. What I've come up with would actually go at the bottom of Majikobe's Deadly Torrent Special Attack instead of here. (This assumes that the Stormshells have standard bonding that works with Majikobe, which I think is a valid assumption.)
"Until the next time you reveal an Order Marker, Stormsheel Warriors you control may not use their Flood Launch Special Attack."
So all together, It looks like this:
FLOOD LAUNCH SPECIAL ATTACK
Range Special. Attack 4.
An unengaged Stormshell Warrior within 3 clear sight spaces of Majikobe may use Flood Launch Special Attack. Choose 4 spaces in a straight line from the attacking Stormshell Warrior. Move the attacking Stormshell Warrior up to 3 spaces along the chosen spaces. If the Stormshell Warrior ends their movement adjacent to an opponent's figure on a chosen space, attack that figure. While using Flood Launch, Stormshell Warriors do not take leaving engagement attacks.
and
DEADLY TORRENT SPECIAL ATTACK
Range #. Attack #.
... Until the next time you reveal an Order Marker, Stormsheel Warriors you control may not use their Flood Launch Special Attack.