I am super new to battling and currently trying to read and catch up on what to do and how to build a weapon set. I have some expendable CSC and was wondering if there are any CS opponents that are worth getting at my lower tier? Or even ones below Tier 4 that are worth it? Or should I wait to purchase some higher level ones?

Thank you for any advice in advance! :)

Personally, I would wait. There are a lot of normal and secret challengers for the lower tiers. As you go up in tier, more and more of the stronger challengers become cash shop ones.

Alternatively, you could also buy challengers like Fuyaira, Fruit Punch, Eventide Phoenix, Decidiwi, or Forj Matriarch that have multiple stages. So you could have their lower stages to battle now and unlock their stronger ones for later.

Okay, yay. Thank you so much for the advice! :)