A particular type of golem designed to be the perfect protector. An intricate personality needs to be implemented into the golem to give it the necessary discretion for its job, but utilizing such an enhanced ego may bring with it the golem valuing self-preservation over protecting its charge implementing this self-sacrifice aspect of a sentinel’s personality has always been the most complicated step in creating one. Thus the golem has to be constructed based on someone who is willing to protect its charge.
However the charge will be equally protective of the template so an extra step is taken lest the charge hinder their protector by trying to protect it instead. The golem is concealed the in an outer layer like a mystic matryoshka doll so it appeared as another template. The abilities of the golem are exactly the same as the golem only higher due to the magical fortification. The sentinel is also highly resistant to physical damage and low level magic and is generally fast enough to prevent its more powerful sorcerous opponents from casting high-level spells, which require more time to prepare while these martial arts skills are entirely contained within the outer shell it also has the skills of the inner template. It may not be as tough as the outer shell but it is much faster, more accurate and more evasive. The shell golem’s core personality also derives from who/whatever is within it. The golem remains in a pocket dimension until summoned. If the outer shell is ever broken its fragments could be taken and reassembled around user acting as armor. The wearer gains the abilities of the outer shell enhanced by their own ki.