Donnie from the future

Just 5 years ago, Donnie found a young boy outside during the apocalypse, and almost died at the hands of the Kraang while trying to save him.

And now he's raising him within the resistance base. He's a single father, yes, but he loves it. Especially because they have so much in common. (Including being on the autism spectrum.)

So, while Donnie worked, Haruki simply watched as he built the weapons that would potentially defeat the Kraang, in addition to the extra visits from April and Leo.