Complex sentence: Debuting in', the six horns of Unicron appeared around Earth in response by the approach of Cybertron/Primus and is named by Quintessa (portrayed by Gemma Chan) as Cybertron's ancient enemy.
Split into simpler sentences: Debuting in', the six horns of Unicron appeared around Earth in response to the approach of Cybertron/Primus. Unicron is named by Quintessa (portrayed by Gemma Chan) as Cybertron's ancient enemy.