Pretty much every scene with Sol is a Crowning Moment of Awesome. Like Jayfeather getting Mind Raped when he detected his presence, how unbelievably calm and composed he is all the time, his deep, hypnotic voice, and this exchange:
Firestar: "Then why are you here?"
Sol: "I came because it was time."
Spiderleg: "Time for what?"
Sol: "Time to come."
And let's not forget how he predicted a total solar eclipse and, knowing it would scare everyone shitless, used it as an elaborate metaphor to (sort of) explain his motives.
This troper firmly believes that he specifically convinced WindClan to launch their attack on ThunderClan so that his predicted solar eclipse would occur right in the middle of the battle and allow everyone to start taking him seriously (and it certainly works, in ShadowClan's case). This would also explain why the attack had no clear motive: can you imagine Onestar justifying himself with "Well, Sol thought it would be a good idea"?
Sol is capable of making the already confusing plot even more confusing in a single sentence:
Sol: "Are you sure you have found the three?"
And in Sunrise, when a ThunderClan patrol comes to take him prisoner, not only does he figure out exactly why they are after him in a matter of seconds, but him calmly agrees to go, offerring no resistance:
Sol: "You don't need to put me under guard, you know, I'm not going to run away."
And when he forms his own Clan and later teaches them to fight just so they can fight off some dogs. When they eventually fight the dogs, most of the cats get ripped apart. Not only does he not help at all, but he calmly strolls in later and tells the survivors that it was their fault for wanting to fight, and then tells them to get him some food.
Lionblaze in the battle at the end of Outcast. He comes out absolutely covered in blood, and none of it is his.
At the beginning of Sunrise:
Tigerstar: *Lionblaze's claws held at his throat* "You'll never do it."
Jayfeather when he leads his siblings in faking a sign from StarClan to restore Blackstar's faith after he'd been led astray by Sol... and then the "fake" sign gets hijacked by StarClan and turns into a real sign. From this, Blackstar's faith is renewed, he drives out Sol, and ShadowClan as a whole is saved from falling apart.
Not just the idea of the fake sign, but the sign itself. As Hollyleaf said: "Only Jaypaw would have thought of digging up trees as a message from StarClan."
Even Leafpool (probably the last cat you would expect) gets one at the end of Sunrise when Hollyleaf tries to kill her, and she asks her whether it would be easier for her to die or go on living. The answer is obvious enough to Hollyleaf, and she lets her go.