As for Jason, I'm either giving him Zorua or Munna. Dreams are merely illusions, after all. (As much as I love zorua though, and Jarrith had a zorua, i'm leaning more towards munna. i'm going more for representative of that legendary's responsibility, less typing.)
Since it's not technically important to the plot, I guess I can tell you why Dia has robots. She had them specially made (likely by Registeel) for her as a personal army of sorts. She has hundreds of them. They're built to be able to easily travel through time, to wherever Dialga is.
I guess I should have mentioned in rp how to defeat these guys? But we'll say this is like looking up "how to defeat these minions" on G(M)oogle. So. These robots are made of a very strong metal, and cannot be crushed or dented. However, it is weak to piercing, and its joints (elbows, wrists, shoulders, knees, ankles, hips, and waist) are weak points as well. These robots have guns for hands. So be careful.
As soon as I have my laptop back, I have an art dump for you guys. (Well, just Cresselia, Dialga, and the robots.)