Alright, so my initial idea failed with the setup because of the way MV handles sprites through events. This caused an issue where you can't use stepping or walking to make these work. So, here's the way I got them to work.
1st: Each event must have 4 pages. First page is the default one that the arrows start with (prolly the one coming out of the walls). Second page requires self switch A to be on, and it will show the next step in the frames for the arrow's path. Third page, same thing, but requiring switch B to be on and the third and final step in the animation. The fourth page is the blank one that requires self switch C.
2nd: Setting up the move routes.
Page 1: No walking/stepping animation. Custom route, wait x frames (I used 10 and it was alright) and use script call Self Switch A: ON (Yanfly's Move Core plugin).
Page 2: No walking/stepping animation. Custom route, wait x frames, script call Self Switch B: ON
Page 3: No walking/stepping animation. Custom route, script call Self Switch A: OFF, wait x frames, script call Self Switch C: ON.
Page 4: No sprite, no walking/stepping animation. Custom route, script call Self Switch B: OFF, wait x frames, script call Self Switch C: OFF
If set up right, the arrow will travel through each frame as if it were stepping, but without requiring any actual movement or that odd issue that stepping has where it'll go backward in the frames instead of looping. xD It works though, and I have tested it.
You can take it a step further and have the first page activated by event touch. By doing this, when the player walks into it they can be made to take damage as if the arrows had hit them. Once hit, then you can set it to turn self switch A on, so the arrow(s) appear to have stopped when they hit the player. There's a lot you can do overall with these! Hope you guys enjoy!
Here's what the spritesheet looks like. For the slits, just place them as another event above the arrows that go up and you're set. The arrows will look like they are going into the walls.