Titus is, IIRC, Captain of the Ultramarines third company, he's a fairly exceptional spehss mehreen, which puts him on a solidly superhuman level to begin with.
Space Marines are super human space knight analogues divided into chapters of a thousand marines each. They have reflexes that allows them to slap bolter fire out of the air, and fight at speeds that appear impossible to track to the eyes of normal men/guardsmen.
They have super strength, as Titus himself demonstrates here:
http://www.youtube.com/watch?v=E3xVrISyhqM&t=4m30s
and here:
http://www.youtube.com/watch?v=IrAIApYnD_k&t=8m06s
He also overpowers and kills Ork Nobs through out the game, which is no small feat.
http://www.youtube.com/watch?v=7dPGuUD9c5w
His armour and weaponry are pretty hardcore, too. Astartes power armour withstands barrage bombs http://wh40k.lexicanum.com/wiki/Torpedo#Imperium
Listed in the Imperium section of Variants, orbital bombardment bombs.
Astartes armour also stands up pretty well to chainswords, which are monomolecular edged chainsaws with adamantine teeth that spin at around 1000 rpm, IIRC.
Will come back with more later.