Barcelona have signed Brazilian right back Emerson from with Atlético Mineiro, But he'll complete the current season with Mineiro and Join Barcelona on 1 July 2019.
I will correct you - he will play for Real Betis in remaining part of season. Betis is perfect choice to gain experience in European football. I haven't seen him playing, but I hope it will be successful transfer same like with Arthur Melo.
Some other news:
Facundo Roncaglia will join Valencia from Celta on loan.
Ryad Boudebouz from Betis will join Celta on loan.
Leo Baptistao from Espanyol was bought by Chinese club for €5.8 million.
Youri Tielemans joins Leicester from Monaco on loan until end of this season. Meanwhile Adrien Silva moving to Monaco from Leicester, also on loan.
EDIT:
Boom! Center back Jean Clair Tolibo from Toulouse joins Barca until end of 2022/23 season. Initially it was agreed that he will join Barca after end of this season, but he will join Barca immediately.