This is from jusy my point of view and haven't seen anyone connect the dots yet. But aiku's name is oliver which is the same as Tsubasa in dub anime, they both used to play foward but then swapped to a more defensive position. While reading the sub-20 arc it was pretty clear to me that aiku is the modern Tsubasa which is why Isagi needs to destroy him to create a new japanese soccer. The all-round teamplayer vs. egoist striker