One of the aspect I love about KyouHaku/HakuKyou is the real reason why Hakuryuu was pissed off with Tsurugi.
Was he bothered that Tsurugi “abandoned” the God Eden before they could have determinate who was stronger? Yes, but, that was just the surface of it.
Hakuryuu was pissed that Tsurugi never acknowledged their rivalry, their bond.
His game introduction is, literally, him getting melancholic when he heard some people mentioning Tsurugi’s name.
He could be angry about Tsurugi betraying the Fifth Sector like any other SEED or that he couldn’t prove he was stronger than Tsurugi, but he isn’t. It’s clear that he missed him more than anything else, and that he doesn’t care about his alignment in the “Free Soccer vs. Regulated Soccer”.
He gets angry at Tsurugi when he learns that Tsurugi betrayed the Fifth Sector for a weak team and have changed to the point of opened up to them. Something he was unable to achieve.
Hakuryuu valued people based on how stronger and skillful they were, and was obsessed with become the “Ultimate Player”, but…he didn't mind sharing his dream with Tsurugi. He acknowledged his power and, even if Tsurugi wanted nothing to do with him and didn't even acknowledged him, Hakuryuu was fine with it because it was Tsurugi's way of being.
So when Tsurugi acknowledged (chose) a bunch of “weakling” as his equals (friends) over him…it was an insult in his eyes and lately become part of the reason of why he wanted so bad to prove him wrong.
As a side note, Hakuryuu is more open to talk about his true feelings with Tsurugi when they are alone.
When they met again, Hakuryuu acts as if he only cares about his betray and getting stronger than him, but then get disappointed when he doesn't full fit his expectations (and not even mention his betrayal again).
The kid was dealing with a lot of opposite feelings, but one side was stronger than the other, the side that was jealous of the Raimon for being acknowledged and chosen by Tsurugi. That's why Hakuryuu don’t get his redemption or even calm down until Tsurugi acknowledge him as his rival.
