Wisconsin native Nick Viall was one of only three celebrities to make it all the way through Fox's 'Special Forces' Season 2

Warning: Spoilers from Season 2 Episode 8 of "Special Forces: World's Toughest Test" ahead.

With Wisconsin grit and continuous resilience, Nick Viall did it.

The Waukesha native and "Bachelor" franchise star was one of only three celebrities to make it all the way through Season 2 of Fox's "Special Forces." The season finale aired Monday night.

Throughout the season, celebrities took on "grueling challenges from the playbook of the actual Special Forces selection process" while battling the harsh elements of winter in New Zealand, according to Fox. The Directing Staff, made up of an elite team of ex-Special Forces operatives, led the recruits through the course's demanding training exercises.

"Life is full of challenges, and to be able to know that you can step up to the plate time and time again is a very rewarding feeling," Viall said at the end of the show. "It's truly something I'll remember for the rest of my life."

During last week's episode, five remaining recruits — Viall, media personality Tyler Cameron, recording artist JoJo Siwa, Olympic speed-skating champion Erin Jackson and "Vanderpump Rules" cast member Tom Sandoval — were captured while trying to escape evasion behind enemy lines.

On this week's episode, the recruits underwent hours of "military-grade" interrogation as their final phase of the course. Two would leave during it.

"The aim of interrogation is to push the recruits to see where their breaking point is," said Directing Staff agent Jason Fox, who was formerly a part of the elite Special Boat Services. "You have to survive by making people think you're worth keeping alive."

Here's a look at how Viall's interrogation went down and why the DS ultimately decided he deserved to pass selection.

The beginning of the interrogation phase

A specialist team, led by a bearded man called "The Umpire," were enlisted to interrogate the recruits. During this phase, "The Umpire" could remove recruits as he saw fit. And, as usual, recruits could voluntarily withdraw themselves or be medically withdrawn by the show.

The DS gave the interrogators a brief rundown of each recruit. When it came to Viall, chief instructor Rudy Reyes, a former recon marine, called him a "gray man."

"We expected him to do better throughout the course," Reyes said. "However, in the last couple of days, he's come on stronger and stronger."

The recruits were put in a frigid holding room, which is where they were held when not being interrogated. They were placed in "stress" positions and in headphones that blared torture sounds, including crying. They had to wear black hoods that covered their heads, including their faces, so that they couldn't see their surroundings.

When the recruits individually met with interrogators, they were commanded to take off their layers of clothing. An interrogator used a big black marker to cross out Viall's tattoos.

"I want you to forget anything that's individual about you," he told Viall. "With that in mind, all these reminders of who you were outside, and what these things meant to you don't apply here."

During this stage, Sandoval was eliminated by "The Umpire." He said the recruit didn't humanize or personalize himself to his captors, but instead, antagonized them. After saying she missed her family in the holding room, Siwa voluntarily withdrew herself.

Their cover story was put to the test

Remember that cover story the recruits were to study up on last episode? Well, the next stage of interrogation put it to the test.

Essentially, the recruits were to say that they were on a conservation trip looking for kākāpōs, critically endangered nocturnal birds.

"The point of the cover story is to give relevances to why you're in a certain location," Jason Fox said in a cutaway. "But more importantly, it's to buy you time."

"I think I'm just going to be my normal self, you know," Viall said on the show. "Before I went on 'The Bachelor,' I was a guy selling software in Chicago. And, if you're good at sales, you're good at solving problems. It's important to be able to be your best self even when the situation isn't ideal."

That worked for him big-time.

When an interrogator asked Viall where his phone was, he said he left it in his hotel room because he's "kind of a forgetful guy."

The interrogator said how stupid it looked that Viall was walking through the hills at night without any way to communicate in case of emergency. "Most people think we're stupid," Viall replied.

The interrogator wasn't buying it. But, Viall insisted he wanted to be helpful — even after water was thrown in his face.

"I think he is really good, isn't he?" "The Umpire" said of Viall.

"He's likeable," one of the DS agents said. "He's made himself worth keeping."

One of the recruits blew the cover

After Erin Jackson blew the cover, she was given a steak meal outside in front of her comrades.

Viall and Cameron, on the other hand, had to play a game — minus the fun.

An interrogator asked Viall and Cameron a series of patronizing questions pertaining to their cover. When they answered by raising or not raising heir hands, cold water was poured onto their heads.

"The real dilemma for the recruit is at what point do you break cover?" "The Umpire" said. "The reality of it is is the difference between life or death."

To keep themselves "alive," Viall and Cameron gave up their cover. Both men, plus Jackson, ended up passing the nearly 12-hours-long interrogation phase.

Nick Viall's final assessment

The DS met privately to discuss whether each recruit deserved to pass the course as a whole.

While Viall was in the middle of the pack, he stepped up at times, Jason Fox said. DS agent Billy Billingham, formerly of the British Army's Special Air Service, said he underestimated Viall a bit, and described him as the "epitome of an operator."

After gathering the final three, Reyes said: "We ask ourselves, who of you, if any, possess what it takes to stand shoulder-to-shoulder with us in battle."

Billingham told Viall that he was a "gray man," but showed resilience and went out of his comfort zone.

"I'd definitely love to win," Viall said in a cutaway. "I think a big part of life is just being resilient and not giving up. If I made it through selection, I'd feel a sense of accomplishment. You know, I think I'd be proud."

Well, Nick, feel all the accomplishment and proudness. He, along with Cameron and Jackson, passed the course.

"The precious few recruits who pass this course will have a sense of belonging, a sense of pride, it's something that will change their lives forever," Reyes said at the end of the show. "I'm so proud of 'em ... It's a bond, it's a family. It's something that's so special, it can never be forgotten."

Viall called his time on the show "a truly life changing experience," in a Tuesday Instagram post.

"To all my fellow recruits, I’ll cherish our time together," he said, giving a special shout-out to Cameron, Jackson and Siwa.

In the post, Viall said he's "forever grateful" to the DS agents for "helping us go beyond what we thought were our limits."