Normally in games when you play as the same character as last time and they have to reintroduce common characters from the last game it comes off as awkward and stunted, 'oh yes you remember dont you I am you long lost brother we met while fighting a dragon in the woods near the secret base of a god.' it sounds so forced and awkward but it is entirely believable that Nero would randomly go into a grand introduction of herself at the drop of a hat.
In the True End route, after the Mind and Soul of Hakuno are merged, Nero and Tamamo immediately begin fighting over him/her. Hakuno's internal response is golden.
Hakuno: So this is Hell.
The two of them keep fighting no matter how hard Hakuno tries to get them to focus on the crisis at hand, causing Hakuno to get so frustrated they eventually just use the regalia to launch a(n entirely pain-free) Noble Phantasm level Dope Slap on them both.
Drawing Artoria out in any of the four stages she can appear in is this when thinking about her Big Eater status: Calling her forth involves eating 5 yakisoba breads in a specific sector without leaving. In short, you're eating her food!
Made even funnier when remembering that Artoria becoming such a Big Eater is also a case of Flanderization for her.
One of the Bond Events in the True End route results in the return of Nero's glory days of naked lion wrestling.
We can finally understand what Lu Bu is saying, well kind of, and it is hilarious, especially as it is contrasted by what the rest of the cast think he's saying. Of course this only applies to Lu Bu's sub-story, but well...
Doubly so when Tamamo is too busy praising Lu Bu for his loyalty while his internal thoughts are all basically, "I am so going to kill you when this is over!" and both Karna and Elizabeth are trying to tell Tamamo how wrong she is, but she doesn't listen.
There's something rather humorous about Gawain's character portrait as it's the only one that doesn't look at the player, instead looking down and to the left. This makes it appear that, when he's angry, he looks royally pissed off at his text box.
Speaking of Gawain: One of his combos has him make a hilarious vocalization as he swings his sword in an X-pattern in front of him:
Gawain: NUNNUNNUNNUNNUN! SABER!
Another for the True End. After Mind Hakuno wakes up and shares the memories that Body Hakuno sent them with Nero to help the latter with understanding what just happened and not long after the two of you force Archimedes to flee for the time being, Nero decides to introduce you to your generals. Hakuno then says they know each of them and proceeds to explain briefly the legend behind each general and their real name (bar Nameless who's past is still unclear to them). Poor Nero is struck wondering on how Hakuno knows so much when this is your 'first' time meeting your generals. Her character portrait while asking Hakuno on how they know so much just adds to it.
Yet another in the True End route, after you and Nero severed Altera's connection to Velber, you are treated to a scene where Nero and Tamamo are competing for who is worthy to be Hakuno's Servant seeing as they are now both the Mind and Soul. What is it that they are actually competing over to do so? A banquet that the two of them participated in, one side is Japanese (Tamamo) while the other is Roman (Nero) and poor Hakuno sees both sides as very delicious. It's funny since Tamamo was noted to be a good house wife (means she should have good cooking skills) while Nero on the other hand... It plays out for a while with the two arguing over which food their Master should taste first while Hakuno just wants them to stop fighting. Then without any warning and no one noticing, Altera jumps onto your lap and gives her common catch phrase from Fate/Grand Order regarding the food on the table. This results in both sides being so surprised at the little girl's sudden appearance that they stop fighting and speaking for a while and Hakuno silently agrees that they are also speechless. Altera then starts talking about the food being 'Good civilization' and 'Bad civilization' with Nero trying to tell her that there is no such thing as 'Good or bad civilizations' and that all civilizations are good, to which Tamamo agrees with. Both try to politely tell Altera to leave briefly as they are trying to 'spend time with their Master' but the young girl remains. Meanwhile poor Hakuno is getting very hungry by just looking at all the food. When all the talk is done and before they start eating, Hakuno makes one remark that could be aptly be read as this, 'Seeing how it's just the four of us in here I don't think this will end well, I really wish it would though.'
Cu's Side Story is this if you consider who the two have had for a Master in the distant past. It takes place after Lancer has killed Ruler, then an unknown figure starts scolding the dead Servant for failing to defeat a mere mongrel. Cue the CG where Cu in a 'not-so-surprised' tone of voice responds to Gil that he (Cu) is now a 'mongrel'. Gil responds back by wondering if he needs to give the dog another lesson as Cu is apparently threatening him to which Cu merely replies that he's patient enough to where he'll listen before fighting, or else his spear would already be through the former's head. Gil accepts this form of battle and the two start saying the name of their respective Noble Phantasm before the screen fades away leaving the Player to guess how the fight ended.
If you unlock Artoria and do her Side Story, the ending is narrated by none other than Nameless unless it's Artoria herself that is speaking or someone else is having their talking part... This can lead to some 'interesting' moments to where you will question if Nameless' 'hunch' on where Artoria could be found is a mere guess or if he actually knew where she could be considering what his own past figure was. Nearly on the same level is that Artoria apparently ordered a lot of food at the place she is last seen in...with a 'horrified' Hakuno staring at all the dishes piling up while Artoria continues to eat.
In the True End route, not long after 'Mind' and 'Soul' Hakuno merge together, they end up having a heartfelt conversation causing Nero to go dere-dere on the tsundere scale as she doesn't know if it's her Hakuno or Tamamo's this results in Hakuno themselves not knowing the answer either. Then Tamamo is revealed to have seen and heard the whole chat...
Nameless is this entirely just as usual with his Deadpan Snarker moments as your ally commentator. He goes from saying things like giving Elizabeth a 'noisy' complaint because of her singing to commenting on Iskandar's Noble Phantasm having a 'bad' name. He also takes more serious situations in a manner where his tone of voice is just calm and he himself doesn't take it too seriously...unless you fight Artoria as a bonus boss to which he ends up panicking to a degree as he talks to you.
In the True End route, we get a pretty priceless expression from Archimedes in the final moments of the game during a scene not long after it's explained on how Titan Altera managed to escape. He first gives the normal frustrated facial expression upon seeing Titan Altera trying to stop him while she is defying her programming and asks how she got free from his Anti-Fortress Trapping Code Cast. You then see why as it turns out that Corroded Elizabeth broke the cage in one swing since she wanted Titan Altera's power for herself. Problem is that Titan Altera had other plans and escaped. Once Archimedes learns this his facial expression can only be seen as a mix of This Cannot Be! and Why Won't You Die? all while suffering his biggest villainous breakdown in the game so far.
It's funnier when you consider that Archimedes has failed his objective not just thrice but four times total in the main story routes. If you compare this to the likes of Kirei and Gilgamesh in Fate/Stay Night it makes him look even worse than these two as they only fail about twice overall and the latter's third mistake is forgivable since the one he was trying to 'kill' didn't die from the injuries he gave her and he was caught off-guard while the former made a complete 180 turn and once again proves why he's still a very dangerous opponent in Fate/Stay Night Heaven's Feel.
Corroded Elizabeth's final moments of screen time in the ending of the True End route. It's funny because she wanted to be the main attraction and lead role by her choice of words and Nero made a decent reason/answer for why that will fail or has failed when the two met up again shortly after the latter's encounter with Rider. Power doesn't mean that you get the main lead, Elizabeth.
Even more hilarious is when she breaks Titan Altera out of her cage with the intent of stealing her power...and then realizes that she's awake and now holding her in her hands.
C. Elizabeth: Am I, uh, gettin punked?
The very idea of ELIZABETH BATHORY being an idol who sings cheesy songs about love is pretty damn funny when you think about it.
During Tamamo's route, Hakuno can't remember Dark Eliza's name and just settles on calling her "Deli." There's even a dialogue option to call her that out loud later on.
People who have seen Fate/Zero and Fate/Stay Night know that Gilgamesh only praises those who he sees as worthy in his view, otherwise he just calls them 'mongrels' or just decides to 'insult' them in his own way. Should you play Altera's Story or do a Free Battle which you end up being in Altera's faction you can get Gil to end up 'praising' you whenever you get X000 kills (X000 represents every thousand enemies you defeat in-game) which makes this both funny that Gilgamesh has to praise a normal 'human' (this is due to Hakuno's real body being down on Earth still) which he normally avoids and awesome since you get one of the few Servants who rarely even see humans as special to see you as being worthy to be his Master. In short he ends up saying:
Gilgamesh: 1,000!? You defeated 1,000 enemies!? I suppose I must praise you then!
There's also the fact that at one point during Altera's missions or when completing one of his side missions, he offers you candy for doing well.
If you get enough KOs, he'll, in the same sentence, call you a moron for killing so many, and that you should visit him later for a reward.
In the True End route, while Mind Hakuno and Nero are on their way to see and try to negotiate peace terms with Tamamo, Mind Hakuno becomes so occupied in their own thoughts on how to deal with Velber that they walk ahead of Nero, who is getting frustrated at their sudden behavior. When they don't apparently hear her shouting for them she decides to snap them out of this trance. How? She basically uses a wooden beating stick and hits them hard enough that they come to their senses and apologize for how they acted. Yes, Nero has another 'Noble Phantasm' specifically meant to be used on those who aren't paying attention.
Nero: Praetor. Praetor! ... Forgive me for doing this but I have to.
Elizabeth's nicknames continue. The most amusing is what she calls Cu Chulainn: Blue Spandex Man.
While most Servants will make some true and honest reasons for why you should heal them if they take too much damage, a few of them make comments that come off as rather hilarious than being serious.
Nameless: You do realize that there is a thing known as First Aid right?note He comes pretty close to telling the player what their Code Casts have or don't have.
Altera: I may have lost 75% of my body but I can still fight.note Apparently she's already been through this so much that losing her physical Servant form means nothing to her.
During the Dawn arc, there's this little exchange between Titan Altera and Hakuno when the latter spaces out a bit and this worries the former:
Titan Altera: Is something the matter? Did you have any trouble sleeping? Did I overfeed you last night, maybe? (blushing and embarrassed) Hmm, I did mix some enemy programs' guts into that meal. They're good for your energy level, you know... *ahem* Hakuno: Wait, what!?I ate WHAT!? I ingested enemy programs, or...installed them, or... That's GOT to be bad for my health, right? Titan Altera: I...thought just a little would be okay...
There's something mildly amusing when you realise that the last part of Li Shuwen's Noble Phantasm animation is a prime example of "Cool Guys Don't Look At Explosions".