Trivia that is canonical in FNaS: Fiercy Forces "Imagine It!"
(This is not an official part of the original FNaS):

The main task of Silent "The Player" is to "SAVE" Luigi after the event of
Maniac Mania and the Night Guards from the previous installments of FNaS, imprisoned in a new game made by Dr. Golden "Preparation"...

P.S. Everyone has been changed. The Character appearances are different in this version due caused by Silent's Memory as the Characters are somewhat connected to "The Player" once she has accepted the rules of the game, that is:
~ Knuckles "Recall" (FNaS 1 Fiercy Forces version)
~ Amy Rose "Remind" (FNaS 2 Fiercy Forces version)
~ Modern Sonic "Reversion" (FNaS 3 Fiercy Forces version)
~ Luigi "Superstellar" (FNaS 4 Fiercy Forces version and after Maniac Mania)
*But he is already in Dr. Golden's "Preparation" Castle (Locaded on Angel Island) used as a lure to bait Silent into Fiercy Forces Arcade Machine, rest of the night guards are in pizzerias, separately located not far from each other on South Island, this part is aka. The "Mergedverse World")
And yes, even:
~ Dr. Eggman "Scheme" (FNaS 5 Fiercy Forces version)
(This is the part of the Evil Plan by Dr. Golden "Preparation" to gain back his human form)

In original FNaS 5 there was an incident called "The Bite of '91" caused by Origin Sonic (a reference to FNaF "The Bite of '83")
Overall in OG FNaS there was only one accident of this kind of event...
While in FNaS: Fiercy Forces, the same event happens again by Origin Sonic "Midday" in this version... plus, with an event that is called "The Bite of '31" (Fiercy Forces event happens in 2031) which is caused by Dr. Golden "Preparation" biting Security Gurad Silent, aka. "The Avatar" into her neck (that is her weak spot causing her of being not able to move at all) in order to get Silent "The Player" into the virtual world in the Evil Ending.
Dr. Golden "Preparation" doesn't want to bite Silent's head, because:
the trauma, caused back in days once he was a human and it probably would cause to infect a damage to Silent's Memory.
"The Bite of '31" is a reference to a second incident: FNaF 2 "The Bite of '87".
Overall: 2 bite incidents, just like in FNaF.

As mentioned above, Silent "The Avatar" is Silent's "The Player" a herself as a cybernetic version in FNaS Game, she serves as to draw "The Player" into the FNaS game from her real world and also separate from "The Player" and turn her into a "Shadow of future self" as the servant of Dr. Golden "Preparation" in Evil Ending...

Silent "The Player" due to connection to "The Avatar" has gained the ability to not being hurt at all.
Even if she could be damaged badly, she can't loose her live.
This is a reference to Michael Afton as he has gained an immortality due to injected a remnant into him from the scooper.
Silent just "Won't Die" and that is the part of Dr. Golden's "Preparation" Evil Plan of getting immortality by forming Silent "The Player" into the "Remant Soul" and absorbing her.

In FNaS Fiercy Forces the main mascots of the Sonic's Hero Tera Pizza Omnia are the Clones from FNaS 1.
(Fiercy Forces is a reference to Security Breach)
Yes, Clone Sonic "Tune-Up!" the main titular face, Clone Mario "Tune-Up!", Clone Yoshi "Tune-Up!", Clone Tails "Tune-Up!" and even '15 Golden Sonic "Memorize" are the represents not only of FNaS 1 Fiercy Forces version, but FNaS: Fiercy Forces as well.
This would be as an interesting reference to FNaF: https://www.youtube.com/watch?v=jiyOWr03z4I&ab_channel=RyeToast (You can skip to 5:34)

Sonic the Hedgehog, aka. Sonic "Tune-Up!" *mentioned above* in Fiercy Forces is also called by Silent "The Player/Avatar" as: Sonic Hazblur.
Where Haz could be a abbreviation to Haste or the H istead of F would be taken from the first letter of Hedgehog.
Sonic is called as well as the Blue Blur, witch the Blur in name HazBlur is an equivalent to FazBear.
I think you get the point of equivalent as well: Blue Blur ~ Brown Bear.
It is a reference and it would be the opposite to Freddy's surname: Fazbear.

The Characters from previous installments (Clones, Animatronics, Phantasms)
know who is "The Player".
They know that Silent is the one who remembers about them, as they want to be remembered, not forgotten... this keeps them "Alive".
Even they are on opposite side, they are more "friendly" towards her, rather being very aggressive as they were facing the Character Night Guards before.
If Silent would be gone, they would be gone too... that's why they want to capture her and imprison, even Silent can restart the game.

Yeah, I think that is the important thing what is going on. That's all, thanks for reading.

Gotta go, by bye!