In episode 32, Lui calls Valt a terrible blader due to the fact that he could see that Valtryek had not unlocked its full strength yet. While this may simply be him acting like his usual Jerkass self, it puts his personal rule of battling only strong opponents into perspective. He is able to tell whether or not bladers have developed strong bonds with their beys. Only bladers who have completely synced with their beys can achieve true strength.
Why is Daigo the one to prove Jin's innocence when Valt and Rantaro suspect the latter of sabotaging Shu, as well as getting enraged at Naoki's deception? Looking back at episodes 23-26, Daigo struggled with the guilt of cheating in his battle with Yugo. He considered that incident his greatest failure, and was afraid that Jin was going to make the same mistake as him. It makes perfect sense that sabotage and deception would now be a major Berserk Button for him.
How come Silas is the only non-Big Five member in Group B of the International Blader's Cup? Simple, Silas has not only battled half of them already without suffering a Curb-Stomp Battle, he defeated the 3rd strongest blader in the finals of the World League, giving him enough credentials to qualify as a psuedo-Sixth Ranger of the group. Given how he defeated three-fifths of the original Big Five, he might as well earned that position.
Free leaving BC Sol for the Raging Bulls seems a little out of the blue...until you remember that he's the No.1 Blader in the World. His teammates had become so dependent on him to the point where they relied solely on him to win. No wonder he decided to leave. He had hoped that with him gone, it would motivate the others to start pulling their weight. And it worked; once BC Sol got their act together (albeit after suffering a horrible losing streak), they were able to start winning battles and eventually advance to the World League.
When one takes into consideration that BC Sol is essentially Free's home where he grew up, his decision to leave becomes more of a case of Cruel to Be Kind, rather than just randomly deciding he wanted a change of pace.
Aiger gets a lot of flak for being overpowered (i.e. coming close to beating Valt in their very first battle after just creating Z Achilles, being able to defeat characters like Fubuki, who had spent 2 years training under Shu; and Lui, one of the Supreme Four and Big Five), but think about it. Aiger has spent his entire life on a farm in the mountains. Years of swinging from tree branches, climbing rocky terrain, lifting heavy metals, and chopping wood has given him some impressive upper body strength. Also, his father is a Bey trainer, so he probably knows more about Beyblade than most other characters as well. With all that in mind, Aiger isn't actually overpowered at all; he really does have more training and experience under his belt.
There's a lot of theories as to what Shu's real motive for becoming Red Eye was, but the most common is that he wanted to get strong enough to defeat Lui and Free. However, if one goes back to episode 49 of season 1 when Storm Spryzen broke, Shu apologizes to Valt for not keeping his promise of meeting him in the National finals, and vows to make it up to him one day. A flashback in the second season even reveals that one of Shu's reasons for going to America was because he was still guilty over breaking their pact. That final battle in the International Blader's Cup wasn't a chance for Valt to save Shu from Spryzen's control, it was another chance for Shu to fix their broken pact. In other words, Shu returned to his old self because he finally had closure.
Lui only battles opponents that HE deems worthy, openly belittles anyone who fails to meet his standards, and views acknowledging strength as a sign of weakness. It really makes one wonder if something happened to him that caused him to become the person he is now. Gabe even mentions in episode 38 that Lui previously lived overseas before coming back to Japan. However, he always kept to himself and refused to interact with the other students. He only started opening up to Gabe after watching him train. Does Lui act the way he does because he was bullied at his other school? Did he once praise his opponents, only to get mocked for it? Or worse, what if he was discriminated against for having a left-rotation bey?
There's some major Fridge Tearjerker regarding everything Shu's been through in his life: His parents are away most of the time, leaving him to fend for himself; he nearly loses an eye in his first battle with Lui, and gets his Bey broken in their second battle, leaving him feeling guilty for breaking his pact with Valt; he loses to the No. 1 Blader in the world, Free de la Hoya, after joining the Raging Bulls; he's then manipulated by Theodore/Ashtem into joining the Snake Pit (where he is essentially subjected to Mind Rape), and finally becomes brainwashed by Spryzen Requiem. And in case you've forgotten, Shu's still only 11 years old! Take in ALL of that, and you're left with a child who SERIOUSLY needs lots of hugs. It's a good thing the Bey gang were all there for him in the end, and were willing to forgive him after what he did.
Thankfully, this was omitted in the dub, but imagine if Xander hadn't been around to stop that parade float from collapsing? Ana would've been crushed to death...
And that's just scratching the surface; think of how Cuza would've felt knowing he unintentionally killed someone?
When we first see Norman Tarver (as his Gold Eye persona), he has a normal skin tone. But when his face is revealed episodes later, he has dark eye bags and unhealthily pale skin. And it doesn't appear to be a trick of the light, either. Just happened to him during that time?
Wakiya is pretty much the sole reason Valt learned about the Snake Pit's existence and about Shu's predicament. What if he had stayed silent?
What would've happened to Shu if Valt hadn't freed him from Spryzen Requiem's control? Would he still try to destroy other people's Beys? Would he still be with the Snake Pit?
What was Theodore planning to do with Shu if he had succeeded in winning the International Blader's Cup?
Minor one, but in Turbo #18, the ones who fell prey to the ship's traps got dunked in the ocean. While the rescue boat was right by the ship...what if Xavier or Suoh (who weren't wearing ocean-friendly clothing at all) actually drowned?
In Turbo #33, Aiger and Ranjiro land in a room where they have to face off against two infinity stadium beys. That itself isn't so bad, but the ceiling in the room is descending, so they don't have time to waste. By the time Aiger taps into his dark resonance, the ceiling is nearly on top of them. One should remember that everything going on at Dread Tower is being broadcast on live TV, so if Aiger hadn't burst the infinity beys in time...both he and Ranjiro would have been crushed to death while their friends and family were watching...
Looking back at the moment where Boa nearly throws his Bey away after losing to Valt is actually even more tear-jerking when taken out of context. Given how Boa by that point had lost all hope and considered himself a failure, Valt was essentially stopping him from attempting suicide.
After the events of Evolution #47, Norman is never seen or heard of ever again. It can be assumed that he went back to the Snake Pit to better himself. Though, considering the Snake Pit's harsh consequences for failure, its possible he mightve been punished, or worse, put to death for his loss.
After watching his battle with Phi, it's pretty easy to see how Shu could've ended up if he were still possessed by Spryzen Requiem.