I read some spoilers about this chapter before it got released and some were hoping they were April Fools jokes. Unfortunately for those hoping they weren't, they are not.
Galan could resist Threader's Overpower and Merlin got petrified when she tried buying time with him. Even without magic power he could pull those off but resisting Overpower could be due to his ruthlessness and the petrification could be an innate ability like Full Counter and Snatch. Meliodas also willingly tapped into his demon power while still retaining his human psyche. Unfortunately, it's still not enough to take down Galan. Even using the attack that killed the female vampire and created the deep crater in the Escanor side story just angered him. I'm worried about the outlook of the current team since Galan struck some rather nasty blows on them but considering that Gowther is back to his original size and one of his arrows can be seen sticking out of Galan's neck, maybe he had an illusionary spell cast upon him? That's what some fans who saw the spoilers are hoping for and the fact Merlin's spell is still protecting Elizabeth, Hawk, and Arthur might mean she's still alive but we don't know yet. The next chapter is called Attack of the Demons so we might not know their fates for a while.
The side text said there will be another gaiden. Not sure who it will be for but I think since we already got some new info on Meliodas' past, it could either be Gowther's or Merlin's turn.