Well, わ is not a topic marker lol.

I think は is the only true topic marker. を and が are more like object markers.

There are other particles but they're not object markers either. They're more like prepositions.

は and が are the hardest to explain. They're almost interchangeable and the sentence would still make sense, but mean something different. が is usually used for emphasis on the object, and in general, は is used on topics that do not vary.

For example, 私はイライジャです。Simply means "I am Elijah" - a fact that never changes. If you change it to 私がイライジャです, it still makes sense, but the situation in which you would use this changes. You're emphasizing "私", and you would most likely use this in a situation where the person has made a mistake on who's Elijah, and you want to correct them to say that *I* am Elijah, not the other person.

Other than that, が is simply an object marker. You use it on sentences like "I like apples". りんごが好きです。

を is just used before a verb to indicate an action.