So, Vader has the massive speed boost. I'm assuming full Empire as you haven't said anyone apart from him and EP. That's +56 speed on top of whatever his modded speed is.
He will be faster than most none GLs, and will open with Force Crush. All these debuffs put him at 100% TM thanks to Palpatine's lead, so he'll follow up with Merciless Massacre and start slaughtering your team.
He cycles through his abilities quite quickly. For example, he'll use Culling Blade as the first and last move in a Merciless Massacre run against a full team.