The £47m arrival of Mbaye and the £25m deal for Harwood-Bellis represent Villa's ninth and 10th summer signings respectively. Villa had generated more than £300m from the sales of nine players, six of whom started May's Europa League triumph in Istanbul. The club's manager, Unai Emery, is confident that the signings will help the team replicate their recent success.
Villa have qualified for the Champions League in two of the past three seasons and won their first major trophy in 30 years after lifting the Europa League. The signings come after a busy transfer window, with Villa also signing Johan Manzambi for a club-record £52m from Freiburg, although the Switzerland midfielder is yet to make his debut due to a knee injury.
Emery struck an upbeat tone after Monday's 1-0 home defeat to Arsenal, saying: "We are happy how we are closing the transfer window. We are not regretting anything and the players who are joining are players that should be enough to rebuild the team with the structure we want."