Trio of Alfheim Summonettes -Sonata Before the Demise- by StudioOguma - Adult Sex Game

In the fantasy underworld of Alfheim, three female summoners by the names of
Rina, Selica and Fiona (fire, water and wind magick) conjure the demon king.

Capture the girls and obliterate their morality in a tower defense game.
Discover and utilize the special assets of each unit type.
Strike and counterstrike, using the powers of captured Rina, Selica and Fiona
to cut massive swaths of destruction through your enemies.

Battles play out in realtime. Tactics of not just strength but also balance are needed.
With the right skill you will deploy unstoppable troops and blast destructive
magic using a consumptive energy called Dark Magic...