[Destroyman]

I'm currently watching W, & I just saw the W X Decade Movie & since all i know of Decade are a few clips & cliff notes, i have a few questions:

1. Have Decade & W met before?
2. Why did Tsukasa have a Skull card?
3. Why does brutally murdering all the Riders save the Multi-verse?
4. Why didn't he have to kill Diend?
5. What was up with the Tackle chick?
6. Why did the old man turn into the leader of Super Shocker?
7. Why did that guy who says "Onore, Decade", turn out to be with Super Shocker? (And how did he grow a moustache?)
8. What was up with "the ultimate lifeform"?
9. Why did Super Shocker design a Giant mechanical elephant? And how exactly was W able to take control of it?
10. How disappointing was it that this was technically the finale to Decade?
11. Why is Tsukasa such a dick?
12. Why is Soukichi so awesome?