When the metallic stone tablet consumed a Holy Master, a huge wound would be repaired. It did not possess too much intelligence since it was just a part that was forcefully cut out from the Mechanical Soul's body and infused with a little soul flame.
It was not aware that it would not survive for too long. The reason why Bain wanted something like that was just to suppress the power of glory in the altar.
Although glory divine spell was especially effective against spirits of the dead, this applied both ways. The unique undead attribute of the Mechanical Soul meant that the glory divine spell had to expend even more in order to achieve the usual effects.
A towering metallic stone tablet was able to suppress the core of the entire altar. In order to utilize divine rune charm array, the tablet had to be destroyed first. In order to do so, one would have to attack it continuously to weaken the soul flame within it.
