Everyone is Class K or higher because of this feat
Time to see if I was correct to place them there.
Important numbers I found with the first few images: War's height (203.3 cm) and Abaddon's height (338.42 cm)
Thanks to the map shown in War's little "radar", we can determine how much mass Straga lifted up: Over 11000 tonnes (Class M)
Note: War could match one of Straga's hands trying to crush him while being greatly weakened (He had lost most of his power and abilities), but is overall much stronger than Straga at full power as seen later when the two fight again. Straga's boss, the Destroyer/Abaddon, is also much stronger. This scales to the other Horsemen as well since they're comparable to War. Samael has stopped a swing from Death with one finger so he's on this level as well.
Slight correction[]
Late correction from KLOL, who claims the car is a 2nd Gen Crown Victoria which is 5.385 meters, and since he's a car enthusiast I'm inclined to agree :p
Let's go step by step this time.
So War is 2.38073684 m, now Abaddon:
He's 3.74795999 m now.
Now the thickness of the street chunk lifted by Straga:
101 px is now 3.74795999 m
138 px is now 5.12097502 m
120 px is now = 2.38073684 m
1277 px is now = 25.335008 m
82 px is now 25.335008 m
187 px is now 57.7761767 m
Volume: 57.7761767 m x 25.335008 m x 5.12097502 m = 7495.87788 cubic m
Asphalt density again: 2243 kg/m3
7495.87788 cubic m x 2243 kg/m3 = 16813254.1 kilograms or 16813.2541 tonnes
Still Class M