User blog comment:Crimson and Darkness/Volume 25 discussion blog/@comment-39.43.144.10-20180506110327/@comment-34061653-20180506135852

Think of it like this. Rias knows that Issei's power has been growing at an incredible rate so she needs anyway to recruit strong people to compete against him. Rias just learned that Grayfia is on Issei's team so obviously Rias needs to respond by getting the strongest church warrior since Issei has the strongest Queen. As for Rias being ruthless and cruel. It depends on how you look at it. When it comes to the tournament Rias and Issei are enemies. Furthermore, Strada was testing Rias resolve knowing how dangerous it would be if Strada fought Issei. But Rias pass this test because she knows Issei has been through many grueling battles and rose to the occasion so why should this be any different? Rias knows better than anyone that Issei is not to be underestimated so she's not taking any chances. Rias had this same resolve when confronting Grayfia and I quote "So long as I fight, even if my oppoent is Issei or you Onee-sama then I will win" Rias made a declaration to which Grayfia smiled at. Rias seeks a power to overthrow her powerful lover and sister and if that power can liberate her team then it will give them more strength than ever.