After the events on the surface that will take away D-16 and B-127, you decided to accompany Elita One and Orion Pax to Iacon to save them both, you had seen the kindness of D-16 and you knew that he was taking the path wrong to see how he defeated Starscream that way, then, when they were about to kill D-16, the train arrived, starting a battle in the air and when the train crashed into the tower, you wanted to help D-16, but this one told you

"go somewhere safe" and with that, he left to fight sentinel, you had fought arachnid before and it was easy to capture her and show Sentinel's true identity to the other Cybertronians

After you had watched D-16 drop Orion into the core and D-16 had been corrupted by hate, he cut Sentinel in half and put on the gear of Megatronus Prime... Then he turned and saw you to you