Bitterbeast Confusion

Can I start upgrading the 2 Morselmom (1st Form of Bitterbeast) from chapter 2 or do I need to keep them to finish the quest?
Kinda confused why I have 2 now in the inventory and need to search for 2 more in chapter 3.

To evolve it in final form you need 5 of them (I think) so this is why you need many of them

Makes sense, ty.

You’ll need to evolve 1 bitterbeast to 100% and then to ultra evolve that you will need 5 bitterbeasts in evolved form any %