Did it as Zeraul P3 with Nova P3 ally. Was a painful 40 minutes. Stupidly lost what little army I had. And mis-clicked the 2nd ability upgrade - chose Blink cooldown instead of Shade cooldown. And went with Telbrus legion instead of Zoraya (got Zerg, but was Air).
TIP: It’s better to turn back & fight to keep an already acquired lock (don’t let Amon’s forces take it back) than it is to get a new one or one Amon’s already taken. Time taken to Re-Activate locks could be used for fighting/clearing instead. And just being at the lock/fighting prevents Amon from taking it.