Ubastet kills three and damages a 4th in single attack.
Playing PVP vs 4 drake rider troops. Used Gorgotha twice to power up other troops, damaging 1st drake rider. Launched Ubastet. Killed 1st drake rider, damaged 2nd and 3rd. 1st drake is spawned as 3rd rider is killed. Then 1st drake is killed and second drake is spawned.
Result of Drake in 1st position, damaged Drake Rider in 2nd position. No troop in 3rd position and undamaged Drake Rider in 4th.