I can't believe that someone made a model of this shitty worm.

Tadatomo's taking the place of True Assassin and although he can't rip out hearts like Hassan-i-Sabbah, Tadatomo has the ability to not only resurrect himself but others albeit as flaming corpses. Zouken's more than impressed by the display of this Assassin's power while Tadatomo doesn't seem all that thrilled by his Master's praise. Can you blame him? He knows what atrocities that this worm thing had inflicted on to his own grandchildren and many others for the sake of immortality and what's more frustrating for Tadatomo, he can't do anything to stop him. If he did try to openly defy Zouken, the old man would use a Command Seal to keep Tadatomo in line and even worse, he might use of those rape worm to control this Ninja. All Tadatomo can do is either just win this War or wait for his Master to lower his guard so he can burn this fiend's soul to hell.

Skeleton by Peachmiku3d
Zouken Matou narupajin © Type Moon Fate/Stay Night
Tadatomo by  torata3220 © Lifewonders Tokyo Afterschool Summoners