GWS Pill synergizes well with Hope Soda, as that item increases the charging time of the Special Meter, allowing GWS Pill's effect to last longer. The CRT bonus also offers more opportunities for Hope Soda's CRT Damage bonus to apply.
Fittingly, this item is very useful for Pavolia Reine. Her Special attack "stores" 5 charges of Tonjok to be used at any time after, so the player can use it liberally to maximize the GWS Pill's uptime. The CRT bonus also synergizes with Reine's own skills.
Skill Damage bonus can be stacked with Beetle for a minimum possible bonus of +140% Skill Damage.
"GWS" stands for "Get Well Soon" in English, but has a connotation of "getting over one's delusions" in Indonesian slang. This item is a reference to hololive Indonesia's Pavolia Reine, as she frequently responds to pick-up line Superchats with that phrase.
The item getting unlocked after dying with Halu also ties into how both phrases are used to shoot down deluded fans.