Generally, stopping at the bathroom at the House allows Sif to think to himself. On one occasion, he tries to use the time to cry, but finds himself unable to.
One citizen of Dormont, a daydreaming woman, says she has a sister and yet she's not consistent whether she does or not between the loops, until Sif asks her. When she tries to talk about it, she starts to freak out as she realizes she cannot remember her sister's name, until suddenly the woman just acts as if she never had a sister in the first place, leaving Siffrin confused and uneasy about what just happened. This all becomes much worse once the truth of Siffrin's home is revealed.
In Act 4, after so many loops, Siffrin becomes completely jaded and treats everything like a play, with him faking most of his responses and reactions, except one, Bonnie's hangout. Not only is his reaction genuine, it's far stronger as he's nearly on the verge of a barely contained anxiety attack at Bonnie saying he should have left them for dead instead of getting hurt, the trauma induced by the King clearly not disappearing anytime soon.
As the loops progress, Siffrin's mental state worsens to the point that he starts showing self-harm tendencies and a distressing apathy for his own wellbeing. This is especially apparent in a talk with Loop about Sif often using Tears to loop, to the point that Sif can imply that he wishes to use his own dagger to loop instead. This causes the normally mocking Loop to react with horror, and yet they're helpless to prevent a force from letting Sif have the ability to do so.
Even worse is that if Sif decides to use the dagger the first time while he and his family members are in the House, the narration text says he's pondering for a bit while holding the dagger, while Loop's voice pleads for him not to do it as a last chance. If you are brave enough to ignore their warning, he starts raising the dagger for a bit, startling Isabeau, who becomes afraid that Sif might hurt himself and attempts to stop him in a panic. However, Sif quickly lets the blade go into him at the split-second the screen cuts to black, as we hear the sound of a blade slicing him and then a thump on the floor, indicating that he has..."completed the job". Of course, he gets better thanks to that Resurrection/Death Loop of his, but still.
You killed yourself. START AGAIN
In Act 5, Sif cries and falls to his knees at the idea that he may be stuck for good in front of Loop before he lashes out for them withholding information. To make things worse, even Loop's taken aback and horrified at how bad Siffrin's mental state has gotten and desperately begs him not to give up.
How self-destructive Sif becomes as they go through the House in Act 5. He does things such as taking more than the recommended painkiller amount, attempting to drink despite not liking alcohol (though it turns out to be just regular grape juice), and cutting himself with a piece of glass.
The "fight" with Mal Du Pays. Being Siffrin's Sadness and self-hatred made manifest, none of Siffrin's attacks do anything to it. And while Mal Du Pays doesn't attack him directly, it brutally tears him down verbally by imitating his friends and targeting Siff's fear of abandonment, causing Siffrin to despair and nearly give up.
The final fight in Act 5, between Siffrin and his friends, except it's not a proper battle, it's Siffrin in the midst of a total mental breakdown and is lashing out due to fear of abandonment. Despite Odile attacking in self-defense, after being berated by the other members, none of them try to attack Siffrin again. If Siffrin doesn't attack the group, he winds up attacking himself instead, and the group can only watch in horror as they try to get through to him.
Siffrin deals a fraction of the damage he does to himself, not only due to his self-hatred but likely not truly wanting to hurt his friends even as he spirals.
Siffrin’s character portrait during this fight. Doubles as a moment of Awesome for the beautiful art and the detail right down to the star you can see in his eye, but it’s hard to describe just how shattered, lost and hysterical he looks at this last moment where he’s finally reached his limit.
Siffrin finally snapping at the Head Housemaiden when she can hear him. It’s not her fault that she’s not been able to help him and as far as she knows this is the first time they’ve ever met, but her finally breaking out of her robotic repeated speech and trying to help Siffrin just sends him spiralling even harder, much to the party’s horror.
The very idea of your home, culture, childhood and family being wiped from existence, to the point that no one can remember anything about it, especially its name. It clearly leaves a gaping hole in both Siffrin and The King that they desperately wish to fill, but no matter what they do, they can't. What's worse is that there's no real good outcome: even in the best ending, Siffrin has to content himself with thefact that he'll never see home again.
The reason why Siffrin wasn't home when his island was wiped out of existence? He had run away from home for awhile, and never thought it would be the last time he'd see his home again.
If Siffrin examines his coin enough between loops, he can eventually recall what made him dislike croissants. One time, he had gone to purchase some at a bakery- but the baker had the same accent as Siffrin, almost outright implying that they come from the same lost island. This was enough to upset and distress Siffrin, to the point that he can no longer eat croissants without remembering that scene.
The culmination of Siffrin wondering if Isabeau will ever touch his shoulder under the Favor Tree in Act 4. Frustrated and desperate for some kind of physical contact, and to hear what Isabeau has been trying to tell him at The End of every loop, Siffrin makes a snap decision and kisses Isabeau out of the blue. The player knows how far gone Isabeau is on Siffrin by this point, and can contextualize his surprised reaction of pushing Siffrin away as genuine shock and surprise because he never would’ve dreamed of Siffrin making a move like that. But the game is through Siffrin’s eyes, and at this point he is spiralling into depression and self-loathing so deeply that he immediately believes Isabeau is disgusted by him for forcing a kiss on him and loops back. After this, Siffrin never lets Isabeau touch him. The memory he gets from this moment, Memory of Touch, is completely full of self-loathing and provides a heartbreaking minus 50 penalty to all of Siffrin’s stats.
Loop. Everything about their backstory and character is just tragic. They're a Siffrin from another timeline (heavily implied to be the prologue game, albeit one where they never beat the king) who, unlike our Siffrin, never managed to get a good ending. Stuck in the loops for so long and filled with despair, they wished to leave it all: and so they were warped into the starlike being we know them as today, and forced to help our Siffrin through his loops, suffering in the knowledge that none of his friends in this world recognize him as Siffrin and that they can never go home.
Should Siffrin lose against Loop in their fight, Loop will prep the killing blow... Only to break down, unable to do it. Despite everything, they're still the gentle Siffrin at heart: and it just highlights how lost they are now that they're here.
In Act 4 Siffrin can start to let their facade slip and be uncharacteristically silent. Isabeau's reaction to this is to tell them a joke to cheer them up. It works and Siffrin laughs, only for the cute moment to be undercut by Siffrin's narration saying "You'll have to remember to laugh next time".
The house is full of charming environmental interactions and dialogue with your party. Gradually though repetition starts to make them lose all meaning for Siffrin, with jokes ceasing to be funny and provoking less and less of a reaction to the point where Siffrin knows them by heart and is simply parroting their lines robotically from a script, impatient to carry on.
Once such example is the "TREE-mendous tree" pun Siffrin makes when talking to Isabeau in front of the Favor Tree. Initially Siffrin's narration saying "No, you will always make the pun" if you try and skip it is entertaining, a reflection of his dedication to bad puns. Later though he adds that he needs the routine to stop him going insane, and eventually has the option to give up on the bit outright and simply remain silent.
In one of the dead end rooms Siffrin can enter by using the crest on the wrong tears (at which point it's impossible to reach the king) is a broken doll. Siffrin can hug it and sadly note that "This doll will never see the end." Thankfully subverted if he picks it up during Act 5 and then examines it in the final act.
