The 21-year-old has represented Spain at every age-grade level from under-16 and has made over 50 appearances for Villarreal since making his senior debut in July...
Barcelona survived four minutes of stoppage time and a late penalty appeal for handball against Jules Kounde to secure a crucial victory.
The deal with Everton was set to be a straight loan until the end of the season with no option or obligation to buy.
Chukwueze also registered the same output in five matches in the group stage of the Europa Conference League.
Chukuweze performed well while Emery was in charge at Villarreal contributing to 30 goals in all competitions since Emery took charge in 2020.