Defensor - Protectobots

The combined form of the five Protectobots Defensor exists specifically to safeguard human life. In many ways he feels about the human race the way a parent would their children and he would give his life away in an instant rather than let one human come to harm. Defensor is emotionally attached to humans on a level that sometimes worries his fellow Autobots. He identifies with them the same way a sheep dog would with its flock or a puppy with its human owners. As far as Defensor is concerned the humans are his "kind." Sadly the titanic robot giant's attempts at personal interaction and friendly exchanges with humans tend to fail. We humans tend to be more wary and frightened of his alien nature and great size than Defensor can understand. Despite this, Defensor is fairly well adjusted mentally compared to almost every other contemporary gestalt.

Defensor's most notable ability is a powerful force field he can create within 50 feet of his person, but it is very fuel consumptive and he cannot maintain it for long. He can also further combine into God Guardian.

(Source: www.tfwiki.net)