From Dragon Quest Wiki

Kasag is a spell that debuted in Dragon Quest Monsters: Joker. It is an attack-lowering spell that serves as the group version of the single-target Sag. Like it's diminutive counterpart, it was the first attack-lowering spell in the series and would remain in use for the Monsters spin offs until the development of the third Joker game, in which it was retired for Kablunt.

Dragon Quest Monsters: Joker[edit]

Kasag costs 10 MP to use and lowers all enemies' attack damage by 50%. It can be learned from:

Dragon Quest Monsters: Joker 2[edit]

Kasag can be learned from all the skills it could be previously. It can also be learned from Missing lynx for 72 points.

Dragon Quest Monsters: Terry's Wonderland 3D[edit]

Dragon Quest Monsters 2: Iru and Luca's Marvelous Mysterious Key[edit]