Just a few weeks ago, Anthony Walker was a university student and comedian - well known among his over 100,000 social media followers for relentlessly trolling Donald Trump's supporters and, more recently, protesting truckers at home.
Now, the Canadian is at the Polish-Ukrainian border - and says he's ready to fight, joining a growing number of foreigners who say they are heeding Ukraine's call for volunteers.
Speaking from south-eastern Poland near the border of Ukraine, Mr Walker, 29, says he was motivated to upend his life in Toronto - including three children - less than a week ago, moved by scenes of the war on the television.
"My wife and I were watching the news coming out of Ukraine, the pictures, the videos. None of it was good," he told the BBC. "I thought to myself - if this was Canada, we would want someone to help."
His initial reaction, he added, was compounded by a dawning realisation that he was "lucky" enough to be born into a stable, relatively affluent country that has never known a war at home.
"We would never be attacked like that. We have that luxury," he said. "I have no ties to Ukraine. I'm not Ukrainian. I'm human. I think that's a good enough reason to come here."
Mr Walker has no military experience. In fact, he says he was deemed medically unfit and rejected from the Canadian Armed Forces three years ago due to haemophilia.
Instead, he's held a series of jobs and occupations, including being a carpenter and truck driver. He's also a certified emergency medical technician - a skill he said he hopes to use in Ukraine. Most recently, he was studying cybersecurity and hacking at a Canadian university.
For now, Mr Walker plans to remain at the Polish borders for a few days while he waits for several dozen former volunteers, including former Canadian soldiers and others from the UK, South Korea, and the US. On Monday, he said he was helping deliver supplies to the Ukrainian military by truck.
He then plans to head to the city of Lviv in Western Ukraine before heading to the front.
The border crossing between Poland and Ukraine, he added, is currently inundated by refugees attempting to leave the country.
"Some have been waiting four days in line to pass to this side of the border," he said. "They're hungry. They're cold. It's not a good situation for them."
Since he announced his intention to head to Ukraine, Mr Walker says he has been inundated by messages from other volunteers hoping to follow suit.
What began as a trickle of messages has become a flood, particularly after calls for foreign volunteers from Ukrainian President Volodymyr Zelensky and other senior officials, including Foreign Minister Dmytro Kuleba.
The calls have prompted thousands of messages on social media platforms like Reddit and Discord from people around the world.
Although the number of people volunteering remains unclear, Ukrainian ambassador to the UK Vadym Prystaiko has said that an "overwhelming" number of foreigners are "demanding to be allowed to fight" for Ukraine.
While Ukraine has said it will arm all volunteers, details remain scant about who exactly they are looking for or how they will be trained, organised and deployed.
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On Sunday, Canadian Foreign Affairs Minister Mélanie Joly was quoted by the Globe and Mail as saying that it is up to individual Canadians to decide if they wish to volunteer and fight in Ukraine - although she was speaking of Canadians of Ukrainian descent.
UK Foreign Secretary Liz Truss has also chosen not to discourage people, saying that Britons "can make their own decisions" about going.
While Mr Walker is supportive of these efforts, he warns that would-be volunteers should be realistic about what it entails, ranging from high costs and lost income to the realities of combat amid the Russian invasion.
He's also worried about his own digital security and says he's rerouting images posted to social media through hacktivist network Anonymous to be scrubbed of metadata before being posted by a third-party.
He believes many volunteers are young and "gung-ho", with romanticised and sometimes fanciful ideas about war. Veteran soldiers on discussion boards for volunteers online have warned that untrained and unprepared volunteers might become more of a burden than a help.
"If you want to come here because you think it's like 'Call of Duty' - don't," he said, referring to a popular war-themed video game. "Grenades and bullets kill. This is not a video game."
When asked if he's concerned at the prospect of facing the Russian army in Ukraine, Mr Walker says that initial jitters have given way to determination, particularly after reports that a child was killed after artillery fire hit a children's cancer hospital in Kyiv.
"I'll do my best to avenge this child," he said. "I feel like I'm doing the right thing."