The Burkina Faso international spent the last three seasons at Olympique Lyon where he racked up 33 goals and 17 assists in 126 appearances.
Villa's statement:
AC Milan new home kit
Brighton & Hove Albion new home kit
Tottenham Hotspur new home kit
Aston Villa new home kit
Borussia Dortmund third kit for the cup
Tottenham Hotspur new away kit
Wolverhampton Wanderers new home kit
West Bromwich Albion new away kit
Schalke's 2020/21 away kit
Rangers 2020/2021 away kit
AS Roma's new away kit
Atletico Madrid's new away kit