Three-Four Kill Type Grind in 2 Minutes
For all the grinders out there, here's a little tip for racking up 3-4 different kill types at the same time. This will grind out kills for: Heavyweight (non-takedown kills), Master of Environment (contextual takedowns), and Wrecking Machine (multiple opponents w/ one takedown), plus the opportunity for some accidental 30 Million Dollar Weapon kills (regular takedowns).
For this method, I waited until I had completed the game (not sure if that matters) and loaded up the Escape Embassy mission on trainee.
Right off the bat you fight 3 guys. Kill the first one hand-to-hand WITHOUT a takedown. Taking down all three at once is a waste of a kill. Once the first guy is down, use a takedown to knock the other two down at the same time. There you have one non-takedown hand-to-hand and one multiple opponent takedown.
Fly through the corridors until you quicktime under the falling gate. Around the next corner is an army dude. Melee him a little if you wanna up your adrenaline meter, but before killing him back Bourne against the wall between the mail cart and the picture frame and do a takedown. He should smash the guy against the mail cart or the picture for a contextual.
Next, go up the stairs and sprint down the next hallway until you come to a guy in a suit who you'll fight. You should have adrenaline stored up, so back Bourne up against the radiator right next to where the fight begins and bash the guys head open on it for another contextual.
Finally, sprint down the hall away from the gun fire and when you turn the corner you'll fight another military guy who busts through the door. Contextual takedown him using another mail cart next to the door he came through.
Once he's down just restart the level and repeat, as the rest of the stage gets convoluted and the kills don't come as quickly. That whole run only takes about one minute and 45 seconds, and you get three contextuals, one multi-enemy, and one hand-to-hand. If by chance you botch one of the contextuals, you'll still get a regular takedown which, if you're like me, you'll need as well anyway.
Hope this helps somebody.