#4 Kalisto
Why: His shot at the Cruiserweight championship is at Survivor Series. The name of Kalisto was thrown around a lot when WWE announced their Cruiserweight division, but unfortunately, Kalisto was drafted to SmackDown. Now, he has a huge opportunity on his hands and could bring in the whole Cruiserweight division with him to the blue brand.
WWE needs to make him look strong before that, and an appearance for the Cruiserweight division on Raw could be a great way to do so.
How: Kalisto could be brought in to challenge any of the Cruiserweight wrestlers on the Raw roster. For instance, if WWE lets him face TJ Perkins on Raw and Kalisto ends up winning, he all of a sudden becomes a huge contender for the title against Kendrick. At the same time, it will hype the Kalisto vs. Kendrick match as well.