I just found out how to make it so when you reach a certain level, you learn the Chaos Skill, and it shows "Actor has learned Chaos Skill" when you level up. (I've spent hours trying to figure out how to make it so that it stops showing up after you learned it, and I've figured it out!)
under Scene Battle 2 under def start_phase5 add this:
@skill_texts = []
if $game_actors[ACTOR_ID].level >= 2 and not $game_actors[ACTOR_ID].cd_skills.include?(CD_SKILL)
@skill_texts.push("#{actor.name} learned #{$data_skills[CD_SKILL].name}!")
$game_actors[ACTOR].learn_cd(CD_SKILL)
end
in other words, if actor's level reaches 2 or higher and you don't already know the skill, then make text in help window:
"(Actor's name) learned (chaos skill's name)!"
Then, actor learns the chaos skill.
I'm just posting this just in case you want to add it to your script, or if anyone else needs to know how to do this. At least I didn't make a request about this.

Note: I haven't tested this without the Easy LvUp Notifier script. I inserted this into easy lvup notifier and it worked. Thanks for the lvup, although I'm a terrible scripter.