Professor Kooper
Professor Kooper is an archaeologist at heart. For years he studied the ruins of both lands, trying to put together their ancient past. Upon a great and rare discovery, he proposed a theory that the Toadstools and Koopas were connected under a single bloodline long ago. That was until the pre-Toadstools transformed the pre-Koopas into beasts of burden to fight against the exotic dangers of the world. While it was well articulated, his theory sounded like he was ridiculing his own people, and he was thrown out of academia. He then embraced the Mushroom Lands, sharing his unique talents with those who would listen to him. Mario and Luigi have gone to him time and time again for his perfect memory of the Koopa Castle's weaknesses and the destination of many green transfer pipes, but now with the Brothers missing, no one but him knows the in's and out's of the Koopa Castle so well.
toadette
Toadette is Toad's younger sister, and she is as spunky as she is eager to help. However, she's not had a chance to prove her abilities, and with the loss of heroes recently, it seems like her chance is coming up. Her abilities are much more focused on the culinary arts and potion making, and her fighting skills are best served with an iron pan or a chopping knife. Had it been Toad's say, she would have stayed in the Mushroom Castle and continued her studies. The old and wise Toadsworth sees potential in the girl and has given his permission for her to venture out on her own. Exactly how she will do that is unknown, but she is eager and willing to do it all on her own if necessary.