Removing Karaoke Effect from .ass Subtitles

[webslingerr]

To explain this best, I'll have to be extremely specific. Here's an example: So in the first and third openings of Attack on Titan, the credits are in white for the Japanese letters and in red for English letters. The english letters have a slash effect (as if they're being crossed out) after a few seconds of screentime. I have subtitles with the lyrics matching this style, the romanji in white and the english translation being crossed out and the effect look as if it were done officially/professionally. However, to my distaste, there is a karaoke effect on the romanji, where the letters are emboldened/become larger for each syllable. I'd like to remove this karaoke effect but keep the slash effect. The issue comes with the fact that these effects appear to have been coded in, and I don't know how to reverse-engineer this to remove the karaoke effect. Any help is appreciated, I really want to get this sorted for viewing with my friends.

[webslingerr]

Forgot to mention this: I am trying to remove this karaoke effect from all openings/endings of Attack on Titan, but keep their effects that match their respective credits.

[netmask56]

Have you tried with Aegisub ?

[webslingerr]

Yes, that's how I learned that this appears very difficult. There are hundreds and hundreds of lines of what seem like code to make the effects tick