What solutions have you tried so far? Did you look for solutions on the Developer Hub?
Ive tried bezier curves
After that, you should include more details if you have any. Try to make your topic as descriptive as possible, so that it’s easier for people to help you!
*Note: the two scripts ARE different, they are different sides of the barrage, one is left, and the other is right*
Please do not ask people to write entire scripts or design entire systems for you. If you can't answer the three questions above, you should probably pick a different category.
The main differences between your effect and the intended effect are:
Character shake
Hand models
If you make your character shake a bit (just like the video you included) then it would look more lively. Also, the models you are using are blocks, while the models your video showed were curved, which make it look like they are blurred from the speed.
They also have a circle effect for the hit, which is a neat detail to help show the force of the barrage.
In conclusion: Your “goal” video have more minor details, which help convey the force and speed of the barrage. I would recommend adding more minor details (such as the ones pointed out above) to help convey the power of it.
That looks like the effect of improper positional calculation. You have obviously done some of this already, but continue using the LookVector etc. Try to tweak and make it work regardless of which axis you are looking at first, and then make sure the fists are rotated correctly.
A 1x1 stud part is identical in all directions, no matter which way it is orientated. You will need to find which orientation is required for it to look right and then apply it in all directions.