Urahara Kisuke he's a super genius and super strong in every way even including hand to hand combat. So, yeah he's strong. This is why he's my fave character from Bleach (well, plus he is super hot and funny). While Ichigo is the MC Urahara basically used him as a tool to fight Aizen, they make that pretty plain in the show. Also why the fullbringer arc sucks since that dynamic is absent...well and it just sucks anyway.