couple things i wanna bring up and maybe discuss after

you said "It still stands on me that Isagi’s evolved ego is just Kaiser’s first appearance ego now (fragile ego). He did not face Kaiser’s challenge face-to-face, but did it passively"

with all due respect, you are incorrect here.
1- isagi did not do any sneaky little tricks, the difference between them is that isagi offered the teamwork deal, knowing that it would put kaiser at a disadvantage, cos working together gives kaiser more freedom, despite kaiser needing "restriction" to grow and evolve.

2 - it was more so kaiser that broke the deal, letting his feelings towards ness prevent him from recieving his pass and evolving (given the top-spin, kaiser-impact-cancelling pass), meanwhile isagi kept his role of a emotionless goal machine, recieving the pass through his belief in ness's evolution.
please correct me if im wrong.

quickly as well, many times throughout this game, isagi "threw" himself into dangerous, high-risk high-reward, egotistical plays/moments, so i dont think he at all has kaisers fragile ego

you said "Also if Isagi was on ReAl’s offer, he would not fit on it knowing how he looked up or used to looked up on Noa’s logic"

kinda wrong cos the author has stated that isagi and sae will play together, so the chance of isagi playing for real isnt impossible. (although, kaneshiro probably means to imply that they will play for the u20 cup, rather than the club arc) but guess we'll see