Thread:Moon Snail/@comment-2189621-20200122063810/@comment-30384301-20200208040635

Adding on to Fork's ideas of side quests, I've got some as well. I would suggest that Green Shadow could be unlocked early in the main quest if she is not the undecided fourth starter character. She can be unlocked when you defeat Re-Peat Boss, one of the bosses. Kyoji could also be unlocked through the main quest, but much later.

The gemstones could be an example of characters that can be unlocked through side quests. They will be hiding inside their castle in Gemstonia from Storm Cloud who is attacking their kingdom and has broken the Rainbow Orb - the very weapon that can stop him. While the gemstones can provide helpful tips that will help you along the main quest, you will have to collect ingredients hidden within the map to fix the Rainbow Orb. Once that's done, the gemstones will join you temporarily to battle Storm Cloud who would have very high stats, and they would have to be included in your party when you fight him. It will be permanent once you defeat Storm Cloud, Diana Diamond will join as a playable character and the other six as support characters.

Another possibility is at a volcano, where you can find Akasha. She has trouble destroying one of her books (Book of the Forbidden Shadow Arts) as it contains a portal to a shadow dimension where her past enemies are coming out from. Her side quest will be a bonus set of stages which will be quite difficult, where you will have to defeat shadow ninjas in another dimension and eventually the Shadow Sensei. Once you complete the set, she will join your party as a playable character.

Assorted Cookie is another possibility, but you will not need to defeat a boss to unlock him. You can find him in Baker Street and give him items you have in exchange for coins or other items, and if he sees you as a loyal customer (i.e. you have been traded with him many times), he will reveal his side quest - collect 10 different ingredients that can be earned by various ways so that he can bake a cake for Rainbow Cookie. If all goes well, he will join your party as a playable character, and Rainbow Cookie will take his place as trader.