Mysterious characters - I want to know who are they!

Emperor Zet (Ressha Sentai Toqger)

He's a leader of Shadow Empire - group of evil creatures who (by hurting people ) are gathering negative energy called simply Darkness. But, in opposition to his minions, Zet doesn't hate light - he loves it! And has an obsession about it, despite of fact, that light hurts him. But what about his secret? Well, when main heroes, who lost their memory at the beginning of the series, regained them, they also remembered a song from their childhood. Next scene was Zet in his palace, singing exactly the same song! Who is this guy? Is he connected with main heroes?

Missy (Doctor Who)

In season 34 of DW, characters who died turned to be alive in strange places. Then they were greet by mysterious woman who called herself Missy. She also described mentioned locations as "Heaven" or "Promised Land". She was also shown spying the Doctor's companion, Clara. Who is that old hag? Old enemy the Rani? Evil side of the Doctor similar to Valeyard? New character? Or even female incarnation of another enemy, the Master? We'll probably get the answer tomorrow, or, in the worst scenario, next Saturday.