Throughout Pokémon Platinum, the International Police agent Looker comes across as somewhat inept, always showing up just a little too late to be of any use against Team Galactic. Then you get to the end of Stark Mountain, and Charon's about to steal the Magma Stone. Suddenly, a Croagunk comes out of nowhere to stop him, and it turns out that Looker was there all along on a stakeout, disguised asa rock. Guess he's not so incompetent, after all.
Not to mention that he was staking-out in that heavy rock costume all that time in a freaking volcano. I'm sure even the regularly dressed people were sweating profusely.
You finally reach the top of Mt. Coronet in Diamond/Pearl/Platinum, in a desperate attempt to stop Cyrus of Team Galactic from remaking the universe. Two of his lieutenants intercept you, leaving you out-gunned... which is when your lifelong best friend shows up. He's been your friendly rival for the whole game, and been pretty much Played for Laughs, the king of hyperactive short attention spans. Not anymore. Now you and he join forces, demonstrating The Power of Friendship as you jointly wipe the floor with the Galactic members.
The entirety of the Mr Coronet/Distortion World confrontation really. Cyrus drags Dialga and Palkia out, making them create a new universe with the power of the Red Chain and then Uxie, Azelf and Mesprit show up to try and restore balance. Cyrus gloats about how pathetic they are for trying to stop him, and then Giratina appears. An enraged Giratina, who can only be described as a dragon made out of Antimatter, then proceeds to drag his ass into the Distortion World and you and Cynthia then follow him. Once you get past the terrifying awesomeness that is the Reverse World you take out Cyrus once and for all and quell Giratina's fury by beating or catching him. Once you've done all that it makes the E4 look a bit boring.
Professor Rowan earns his status as a Badass Bookworm, by taking on a load of Team Galactic Grunts and holding them off for long enough for you to arrive. The grunts all comment in surprise and frustration that he's tougher than he looks.
Even better is that at the beginning of Platinum, Lucas/Dawn is surprised he keeps TMs around, which implies that Rowan does not actually have any Pokémon on him. Thus, he's fighting off the Galactic grunts with his bare hands.
Not only that, but it can be implied that he used to be a champion before Cynthia. Most of the time, only champions or past champions are allowed to go in the special room to immortalize your efforts. In this game, you're taken to that room by Cynthia and Rowan.
Give Team Galactic some credit. Right up until the end, they were winning. They successfully captured five legendary Pokemon with little interference (the player consistently showing up just a little too late), and only lost in the end because of something nobody could have seen coming under the circumstances. It took the Pokemon equivalent of the Devil showing up to stop them.
There are level 100 wild Magikarp in the Resort Area. How the hell did they reach level 100, being incredibly weak with only Flail and Tackle to attack with (neither of which get STAB)? The fact that this encounter event exists is an awesome moment for that fish. Until you realise it can't evolve.