I recently battle Mama Mush for 50 times, hoping for a special item that can be combined into a special tome of some sort. All I got in a Tome of Ice. This is pretty daunting. Is it real or I was trolled? I also hear if I battle Erdo and Shavam for 50 times. they'll drop loot that can be combined into another tome too.

I think you are confusing loot. Some opponents drop tattered scroll pieces that can be combined in genetech to make scrolls. for mama mush it's at win 75. Many opponents can be farmed for special loot. Special loot includes mod crystals, mage amulets, and the tomes like you just got at win 50. A guide for all loot and which opponents drop them is here:

https://subeta.net/forums.php/read/881230