Given the spoilers for My Hero Academia chapter 374, it is likely that Twice, even after his death, can still influence the outcome of the war. The villain met an unfortunate demise after getting stabbed by Hawks and using the last of his strength to save Toga.
Twice aka Jin Bubaigawara was mentally unstable, something he would embrace as a villain. His identity crisis led him to insanity. Without his mask, he suffered from specified dissociative disorder (OSDD). He would panic and threaten to "split" until he had his mask back on to become "whole".
Before his death, he showed immense growth. In the battle against the Meta Liberation Army, he faced his greatest fear, shattered his limits, and unleashed Infinite Doubles: Sad Man's Parade - a move so overwhelming that even Re-Destro seemed nervous.
Toga and Twice shared a peculiar type of bond in My Hero Academia. She cared deeply for him as a comrade and had a soft spot for him while he seemed to be madly in love with her. Before dying, he apologized for not protecting her and found peace in being able to be useful to his true comrades, the League. Strange indeed, but loveable.
My Hero Academia chapter 374: The return of Sad Man's Parade could change the course of the war
Back in My Hero Academia chapter 341, Dabi was seen handing Toga Himiko a vial of Twice's blood. At the time, the reason for him doing so was unknown and left fans puzzled.
Speaking of blood, Toga Himiko possessed a unique quirk called Transform. It allowed her to physically transform into another individual, right down to their voice, upon ingesting their blood. The more blood she drinks, the longer she can stay in that person's form.
Recent spoilers for My Hero Academia chapter 374 ended with Dabi arriving where AFO, Endeavor, and Shoto were, accompanied by two Twice clowns, seemingly made by Himiko Toga. This more or less makes it clear how Twice's blood was used. Dabi may have known the extent of his comrade's quirk and collected a sample for Toga in the event of his death.
So now, even with Twice dead, he was not truly gone. If Toga was able to make two clowns, it was very likely she could make more. She was intent on using his blood the way Dabi suggested in My Hero Academia chapter 341, and this was the perfect opportunity to do so.
A stupendous number of doubles would be the perfect edge the villains would need over the better-organized heroes. Besides, using her best friend's powers to land a fatal blow to the heroes would stand as the perfect revenge for Toga. It would serve perfectly as posthumous redemption for Twice.
It would be a task the villain would love to take on to prove his worth to the League. Now, it could very well be taken up by his precious Toga and take the form of her Sad Girl's Parade.