As Terran
Make:
Ghost
Viking
RavenEMP and detection first, then Vikings can fight the fleet cleanly.
Open in the counter tool with Mothership tagged ->As Protoss
Make:
Tempest
High Templar
ObserverFeedback support and Tempest range stop the cloak field from deciding the fight.
Open in the counter tool with Mothership tagged ->As Zerg
Make:
Overseer
Viper
CorruptorDetection plus Abduct turns the Mothership into a pickoff target.
Open in the counter tool with Mothership tagged ->
Zealot
Adept
Stalker
Sentry
Immortal
Warp Prism
Colossus
Disruptor