In Fate/Stay Night, Masters and Servants should probably be at least okay at working together, even if they don’t actually like each other that much. So the fact that Assassin and Caster don’t actually get along all that well doesn’t necessarily mean that they won’t work well as a team.
Plus, the fact that Assassin wasn’t created quite like other Servants also means that things might be very different for them as a pair. Here are five reasons Assassin and Caster work well as a team and five reasons they shouldn’t be one.
10 Perfect Pair: Servant Summoning Servant
Caster and Assassin are a very unique Master and Servant pair because Caster is also a Servant. This makes their relationship pretty different from other Master/Servant relationships.
In some ways, it’s probably better, because Caster knows exactly what is expected of a Servant. Plus, her partnership with Souichirou Kuzuki, in which he’s the Master and she’s the Servant, shows that she also definitely knows how to behave like a Master.
9 Not: Assassin Hates Caster
Assassin is not very interested at all in being Caster’s Servant. He actually hates her, and he’s constantly thinking of ways that he might be able to get away with killing her.
This isn’t ideal for any Master and Servant relationship, but it’s particularly bad between these two, since they’re both Servants. They should be able to come to an understanding on this basis alone, but that’s not the case.
8 Perfect Pair: Assassin Is A Fake Servant
Because Servants aren’t supposed to be able to summon other Servants, Assassin isn’t quite a real Servant. That means a lot of things for his abilities, but it also means that he relies on Caster for a lot of things.
While it’s not ideal for him, it actually makes for a pretty good partnership, since Caster is actually necessary for Assassin to exist.
7 Not: Assassin Has Fewer Abilities
On the other hand, Assassin’s status as a fake servant means that he has fewer abilities than regular Servants. This is bad news for him because it makes him less powerful and therefore puts him in more danger during battles.
It’s similarly unhelpful for Caster, since she has to rely on him during fights, even though he’s not as useful as he could be.
6 Perfect Pair: Assassin Is Totally Reliant On Caster
To go further into the point above about Assassin being a fake Servant, it should be pointed out just how limited Assassin’s life is without Caster. Caster is the sole supplier of Assassin’s mana, meaning that he has very little mystical ability without it.
He also is totally unable to leave the grounds of their home without her. This might sound like a bad thing, but it definitely gives Caster an upper hand for controlling him and forces him to do her will, which is generally good for their goals.
5 Not: Assassin Doesn’t Care About The Grail
Speaking of goals, the reason that Caster summoned Assassin in the first place was so that he could help her win the Holy Grail War by fighting in it alongside her.
While he does actually do this, because he doesn’t really have a choice, he doesn’t actually care about whether or not they win. The lack of motivation could possibly make it harder for them to achieve the actual goal of winning the Grail.
4 Perfect Pair: Assassin Just Wants To Fight
Considering that Assassin was created with the sole goal in mind of having him fight in the War, it’s a good thing that he’s really interested in and motivated to fight other Servants.
The biggest excitement of his life is a really good sword fight, and he actively seeks these out. It also makes him a really good defender of the grounds where he and Caster live.
3 Not: Assassin Is Constantly Mocking Caster
Caster has a lot of power over Assassin, so it’s probably no wonder that he isn’t all that interested in being civil toward her. But he particularly makes a point to be very mocking whenever they talk to each other.
This cannot be a great way to foster a relationship between them and certainly can’t make it easy for them to discuss strategy or come up with ways to win battles.
2 Perfect Pair: Caster Can Control Him
The lucky thing about being a Master is that if a Servant doesn’t want to do your will, you can always make them with Command Spells.
Some Servants are really powerful, and it’s more difficult to use Command Spells on them, but in Assassin’s case, due in part because he’s a fake Servant, Caster is able to command him to do her bidding, even when he’s feeling especially ornery toward her. It’s not a great way to have a partnership, forcing someone to do things against their will, but it is an effective one.
1 Not: Assassin Doesn’t Take Orders
It’s lucky that Caster has those Command Spells in her back pocket, because Assassin is absolutely not interested in being her Servant in any way.
This includes generally taking orders from her in battles or in order to guard their home from intruders. A Master/Servant relationship would definitely be better served by two people who respect each other enough to work together, and this is definitely not that pair.