>>149929376
It's a bit of a desperation move since Dev-pretending-to-be-Jacky knows Etienne is growing more powerful as time goes on, and since he had to reveal he's not actually a Superpower to stop Eliza killing him, it's a ticking clock from that point since Etienne will read her mind and know.
Etienne, in typical asshole telepath fashion, significantly downplayed the extent of his already frightening abilities. Everyone thought his body was fragile but if he died everyone in range would die of a psychic contagion or death throes wiping out continents.
As far as killing him unprovoked that's honestly not that big an issue. Eliza is obviously okay with it, Jacky is really Dev who's her husband, Etienne threatened to murder Heavy 's entire family and his child just a while ago, Etienne revealed he could possibly control Heavy's son who's the 7th Superpower making everyone anxious, and Valentina is anti murder but she herself has considered killing Etienne and won't destroy the world to avenge him.
IF he was dead it would actually be a pretty clean resolution and most of the survivors could get along (especially since Valentina and Eliza aren't very ambitious to begin with).......but Etienne surviving means the whole things gonna be a shit show since he can reveal Jacky Magus has been dead since The Queen, which means Heavy might try to kill him before he can build back up the Pyramid as revenge for the "leaked" laser satellite