I felt that this is gonna be a possible story for 2 crossovers, Team Fortress 2 and the Persona Series.

Prologue: The Power of The Wild Card

January 20, 2015
6:30 AM
Badlands, New Mexico

It was a sunny at the NJC Elite Force Headquarters and there's a 1 year off for all recruits so they can enjoy more with their lives. The Captains are really taking some time off for their hard work. They even brought Niko, Aaron, Wolfe, Clyde, and Kaya into the party.

Niko: Thanks, Neil for bringing the 5 of us into your party.
Wolfe: We appreciate of your support, Neil.
Aaron: Neil, you did just well helping our backs during the war and a party is a good reward for you.
Clyde: With your support, we know victory in our hands, Neil.
Kaya: My friends, Neil is truly a great leader in bringing an end to the Gravel Wars.
Neil: Thank you very much, fellas. I couldn't have done it without you, guys.
 
As the party goes on, they enjoy the fun times together until they heard a mailman with a letter from an unknown sender. Niko called Neil, Heidon, and Lejohn to read the letter.

Neil: (Curious) Hmmmmm......
Niko: Well?
Neil: This letter...... is kinda unique
Kaya: Niko, the sender.......
Niko: Kaya, who sent this letter to him?
Kaya: The Velvet Room, Niko. You heard it before?
Niko: Not at all, Kaya.
Kaya: Well, Heidon may give you the details of this.

Niko became confused with Kaya's Answer but Heidon steps up to give him the details about the Velvet Room.

Heidon: So you want to know the knowledge of the Velvet Room, right Niko?
Niko: Yeah. Tell me about it.

So Heidon told everything about the Velvet Room, including it's residents and the power of Persona and the Arcana. Niko, now has the knowledge, calls Aaron, Wolfe, and Clyde to talk about what he heard.

Aaron: I still realized what our future holds when its residents showed up.
Wolfe: We may gonna find out for sure.
Clyde: Looks like we're better be on guard if we know more about it.

During the conversation, the door bell rang. All heard it and they must answer the door to find out.

Lejohn: Someone's want to come in. We shall find out who.
Neil: Alright! All of you, stay with me. We know what's up.

As he opens the HQ's Main Entrance Door, 3 people wearing outfits in Blue appeared from out of nowhere. Neil, Heidon, Lejohn, and Kaya have recognized them as the Velvet Room Residents. Their names are Elizabeth, Theodore, and Margaret, along with Marie. They'll proceed to the meeting room where they discuss of what's happening right now.

Margaret: I see, we have come here to find you, Neil. We know you have the potential to use the power of the Wild Card.
"Neil nods in agreement and told them that his friends and his 2 Top Captains also have the potential, saying that they might learn more about the Wild Card's meaning."
Elizabeth: Are you sure that this is possible, Neil?
Neil: I'm sure about it. Heidon, Lejohn, and my best buddies have been with me during our hardships and battles we fought. We never lost the battle once. Now they need to face their newest task through these events: To know their own potential, the power of Persona, and the meaning of the Wild Card. That's all they need to know, and I can fight with my own life. We won't stop until our job is done.
Kaya: True, I shall learn more about them. Also, it's a pleasure to meet all of you here. 
Marie: Whatever, but I felt that this is the 1st time I came to this place, the NJC Elite Force Main Headquarters.
Theodore: This place feels it's my 1st time being here. Is anyone have a drink for me?
Neil: Theo, I give you a can of Coca-Cola if you want.
"Gives Theodore a can of Coke"
Theodore: Thank you, Neil.
Neil: You're welcome, Theo. Alright, looks like these events will be part of new journey and adventure. 2 worlds will ultimately unite and our antics and shenanigans will ensure that victory will be in our hands. Ready up, all! We got a journey to start!
All: Right!

And so the story has just begun!