I loved that OVA... Where Suzaku beat the living crap out of Lelouch because he was mad at Britannia... <3 Bratty Suzaku, he's simply adorable, and a master at martial arts. (SPINZAKU go!) I wish he was bratty more in the actual series. But I love his sweet, humble, noble side too.
Fine... I'll just start off with a chronological description of Suzaku as I see him then. *takes deep breath*
The Japan Suzaku grew up in was a Japan he was proud of. It was a country that was strong, emanated with power, and was simply perfect through his eyes, then the eyes of a child. His days were spent in temples surrounded by blooming sakuras, training with his sensei, Tohdoh, striving to make himself a worthy heir to the noble name of Kururugi.
And then Britannia starts making an influence, or at least, Suzaku becomes aware of the empire's desire for Japan, a prime source of Sakuradite, the most valued element in the world. He hates them for beginning to steal away his home, and when Lelouch shows up, he has no mercy for this Britannian prince who has invaded his world and country, a pathetic part of that cursed country that was starting to tear up all he had ever known.
But unexpectedly, he was able to become friends with this foreign prince and his blind sister, after learning that Lelouch was no different than he was, a equal, a friend in the war that was starting to break out around them. Suzaku's feelings for Japan, for the countless dying everyday causes him to confront his father, discovering the man he loved and idolized wishes to fight until there is nothing left of his beloved homeland but leftovers for scavengers like the Chinese Federation and the European Union. In a moment of naiveness, rashness, anger, and his sealed passion, he murders his father, tearing apart Japan's last hope of victory and essentially handing Japan to Britannia with his own hands.
It's quite obvious Suzaku did quite a bit of reflection in the years following, abandoning his pride as essentially a Japanese prince, throwing away the influence he could have made as a rebellion leader for the Japanese with his heritage alone to join the unthinkable- Britannia. And his loyalty to his adopted country has been shown too many times to count, and it's all in hope of achieving his farfetched dream of becoming the Knight of One, and obtaining Japan to govern and liberate from the cruelties forced upon them by former leaders. To leave his set path and walk the other way showed bravery and determination towards what he believed was right, gaining the new world through peace instead of war, to lead it from its destructive state to how it was before chaos erupted, a naive wish, but one he worked hard to accomplish.
As an Honorary Britannian, it was likely he'd be stuck in the lowly position of Warrant Officer had it not been for his chance encounter with Lelouch in the Shinjukj ghetto, and his unfortunate(yet lucky!) injury which led him to pilot Lloyd's creation, the Lancelot. However, soon after, he is accused of being Clovis' murderer, tortured, beaten, silenced, anything that would get him to declare himself guilty.
But in this dilemma he stood strong against both Britannia and Zero, separating himself from the latter, and placing himself in the hands of a nation that cared less for him than they would for an insect, realizing which one he could create a better future out of. And hardly a week later, he defended the very man that attempted to sentence him to death from the Purist faction, a show of his magnificent loyalty that beats all odds.
I won't go too far into his relationship with Euphy other than simply stating that he fell in love with her, and that they had been prepared to face the future together when Lelouch was forced to kill her, taking away the person who had become someone to live for, another loss for him. His hatred for Zero is hardly unwarranted- what would Lelouch do if Nunnally was murdered in front of his eyes? He wouldn't very likely sit around and cry about it, right? He'd get out there and avenge her, the demon of revenge as he mercilessly took down his enemy. So why does everybody treat Suzaku's hatred of Zero as a sin of some sort? It's only expected, and Suzaku fully deserved the opportunity to take down Euphy's killer.
In fact, that he hesitated at all in attacking Lelouch, that he brought him to the Emperor instead of killing him outright is pretty admirable. With Suzaku's impetuous nature and generally brash actions, it must have taken all of his self-control to keep from killing his best friend, a man who betrayed him, lied to him and the world. To exchange Lelouch for a promotion may have been a despicable act of the circumstances were not put in play, but they were.
Why should he look upon Lelouch as anything less than an enemy? He's a threat to Britannia, a liar, a backhanded trickster who never fights fair, a cold-blooded killer, and I could go on and on about Lelouch and his shortcomings, but I think you get the point. Combined with Suzaku's ultimate dream and the hatred he held for Zero, Lelouch's alter ego, the exchange was a wise one, one that showed his desire to help Japan, even if it meant sacrificing his closest friend, though, his closest friend had just betrayed him, so there's not much more to that end of the story.
... ... Can I save R2 for tomorrow? I need to work on my fanfic now. Perhaps that was both informative and persuasive for ya, Chelsea.