General question about sword slash vfx

anyone can point me in the direction on how the vertical/horizontal slashes are made?

This would either be a ribbon following the position of the sword, or a mesh in the shape of an arc, that is revealed in sync with the sword swing.

The trail would be like this https://youtu.be/QFBqyypSHis?si=sTN58n0TeEv5F0J6
And the mesh would look like this
https://youtube.com/shorts/biCtOMxfKxU?si=2MO3Qw27z_UkiQgI

hmm yea i got the slashes working, but im rly confused on how to get the straight cuts
looking right

Ah, my mistake. You could probably do that with stretched sprites or mesh planes!

but how do i make them always have thickness, cos if i use a plane if i face it head on, the player will see nothing, as it is facing the side of the plane.

i tried playing around with locking the axis of the plane, but nothing seems to work out

looking for something like this

Both Unity and Unreal should have an option where the sprite has a locked axis, but still faces the player. With that setting, you would set your particle system to local space, so as the system gets rotated a certain direction, the particle also angles that direction without needing any kind of velocity alignment.

After that, however the game’s impact fx system is set up will usually angle the direction of the particle system based on either the angle of the weapon impacting an enemy, or a specified direction that’s linked to the direction of the attack animation. Ex: if the weapon swing is vertical, the impact will always play vertically, regardless of where the weapon hits the enemy