Now that you've added the thermal paste, go back through this guide, retracing your steps until you've completely reasembled your laptop.

Fire up MSI Afterburner, Intel Extreme Tuning Utility OMEN Command Center, or your favorite monitoring program and check your temps/thermal throttling while gaming.

Now my temperatures have gone down about 5 degrees centigrade during gaming, and about 10 degrees on idle.

The biggest improvement is that your OMEN will no longer thermal throttle. I have noticed a 20-40fps improvement in all of the games I play, including Overwatch, H1Z1, League of Legends, Counter-Strike, and BeamNG.Drive.