A lot of the side quests in Scarlet Nexus will be eliminating certain types of enemies or killing them in various ways. The first few side quests are exceptionally easy to accomplish.
One such side quest called Surprise Test Cont. is to find an Other called Wither Sabbat and eliminate two of them using a Brain Crush. To find this enemy is fairly straightforward. Use the fast travel system and teleport to Mizuhagawa District—Construction Site, or Kikuchiba—Mid Level-Shopping District.
We recommend the Mizuhagawa District—Construction Site to head to first. Once you have arrived, head straight for the massive clearing, where the giant hook is dangling, and after a few battles, one will spawn. For the Kikuchiba—Mid Level-Shopping District, keep going through the level until you get to the parking lot, kill the Other's that spawn, and then one will appear.
Remember, you need to kill Wither Sabbats in a Brain Crush. If you eliminate them in any other way, then they will not count towards the quest completion. To do this, you need to empty the Crush Gauge and press LT, R1, or G to finish them off with a Brain Crush.
This is best to do on Hard difficulty, as on lower difficulties, you will probably kill them before the Crush Gauge has been fully reduced, and you have to leave the area and come back for them to respawn. Use SAS Pyrokinesis and attack the weak spot on their back—this will deplete the gauge faster than the health bar, allowing you to use a Brain Crush.
Check out all of our guides for Scarlet Nexus on PGG.