
Tip: Make a party with two of the required summon/characters + a fast group damage dealer and you can clear the character usage missions while also farming the required monsters.
Mindflayer Types x15

Story Act 2 Chapter 4: Uncanny Closet Pt. 1 (Normal difficulty) has 5 Mindflayers in 4 waves, completing the mission in 3 fights.
Note: If you haven’t unlocked this stage yet, you can go to Vayne’s Lost Chapter (Conqueror’s Duty Pt. 11 – Normal) for 3 Mindflayers per fight.
Imp Types x10

The Heretics Event’s Co-op has 2 Imps in 3 waves, so you can easily farm this objective along with the event rewards.

Thanks
To the DFFOO “Monster Hunter Guide“, an initiative to list all monster locations in the game (maintained by Marvan09).
To @xcaliblur, @mzpro2, @infinitus and @Lumine who also contributed tips for these stages in our public DFFOO Telegram group, which can be found here: