It wouldn't be a surprise to me, if you only have Avenger's explanation and memories to go off of. He is, after all, a most extraordinary case.
To summarize, we are Heroic Spirits - those who died and became legends - summoned to this world to battle for one all-powerful wish granting device - the Grail. The mechanics are not so important, but fundamentally, we cannot exist in the living world without someone to tie us down - a Master.
Ordinarily, our physical needs are twofold: not only do we require a binding agent to keep us in the living realm, but we also need spiritual energy to allow us to continue surviving. Now - here, in Hell, we don't require either to exist, likely due to demonic intervention.
However, a Master fulfills more than physical need -
We Servants are summoned for them, after all. We exist to fight for them, to protect them - and they in turn fight with us, guide us, and understand us.
Though Hell has seen to our physical needs as Servants, it has not met with our existential need, in order to be complete.
Re: Day 112, evening
To summarize, we are Heroic Spirits - those who died and became legends - summoned to this world to battle for one all-powerful wish granting device - the Grail. The mechanics are not so important, but fundamentally, we cannot exist in the living world without someone to tie us down - a Master.
Ordinarily, our physical needs are twofold: not only do we require a binding agent to keep us in the living realm, but we also need spiritual energy to allow us to continue surviving. Now - here, in Hell, we don't require either to exist, likely due to demonic intervention.
However, a Master fulfills more than physical need -
We Servants are summoned for them, after all. We exist to fight for them, to protect them - and they in turn fight with us, guide us, and understand us.
Though Hell has seen to our physical needs as Servants, it has not met with our existential need, in order to be complete.
[ with a pause, waiting for her to digest ]