The Russian opposition politician Ilya Yashin, freed from jail last week as part of between Moscow and the west, has said turning Russians against the war in Ukraine will be his focus now he is at liberty.

“I want to explain to my co-citizens in Russia that this war is a tragedy not just for but for Russia too,” Ilya Yashin told the Guardian in an interview in Berlin. “As long as [Vladimir] Putin feels support from the population, he will feel confident.”

Yashin, who was released to , addressed a rally of more than 1,000 supporters in a Berlin park on Wednesday, imploring his fellow exiles – many of whom had left Russia since the full-scale invasion of Ukraine in February 2022 – to try to influence their friends and family who remained inside the country.

“If you can find the strength and desire, please engage in anti-war education,” he told the crowd. “Try to return to at least in your thoughts and your communications, because our people are there and we have to talk to them, we have to pull them out of the world of pro-Putin propaganda.”

The next day, he met the Guardian in a cafe near the Berlin hotel that now serves as his temporary base. He admitted he was still somewhat disoriented, a week after the exchange that unexpectedly gave him his freedom. Two weeks ago, he was in a Russian prison cell two years into an eight-and-a-half-year sentence and he still makes regular doubletakes, struck anew by the sudden, dramatic transition.

“I hope that next week I will be able to find an apartment, move out of the hotel and unpack some of the things my mum brought me from Moscow. I need to orient myself, remember how to eat breakfast, work out where to go for a walk, how to use public transport. Everything is new, I need time to adapt,” he said.

Yashin, now 41, was arrested in 2022 over comments he made in one of his regular video streams, in which he discussed Russian atrocities in Bucha, the town outside Kyiv that was occupied during the early weeks of Russia’s full-scale invasion. He was on charges of spreading false information about the Russian military. He noted, proudly, that the video over which he was jailed had racked up 2m views.

The exchange last week included the US citizens Evan Gershkovich and Paul Whelan, but most of the were Russian political prisoners.

Yashin surprised many when he the day after the exchange, looking irritated and upset to be there, and calling his inclusion a “forced deportation”. He pointed out he had always said he did not want to be swapped, insisting there were other prisoners in poor health more deserving of an exchange, and certain that a Russian politician should be in Russia, whatever the circumstances.

“A voice heard from inside Russia, even from in prison, especially from in prison, is much more convincing than a voice from outside,” he said at the press conference.

A week later, the emotions have calmed but sentiment remains. Nevertheless, the possibility to see his parents, who flew in from Moscow earlier this week, and to enjoy small freedoms such as sitting in a cafe and ordering a coffee, or choosing what time to go to bed, is exhilarating.

“I have very contradictory emotions, they’re exploding my head from within. It would be stupid to deny that I’m happy to be able to walk freely in the street, breathe fresh air, to open and close doors when I want to,” he said.

He does not yet know where he will live or what his future will look like. But he said he planned to keep doing what he was doing before, even if he now had to do it from exile.

“People don’t believe there was a massacre in Bucha, and it is all a fake,” he said. “Well, we have to explain that this was real, that it’s something we should feel ashamed of because it was our co-citizens who did it.”

He said that while in prison, he had read books about the denazification of Germany and felt that there could be some lessons for the Russia of the future. “Germans were taken on excursions to death camps, to show that it wasn’t some kind of propaganda but it really happened. That’s what we’ll have to show people, too,” he said.

Yashin said that during his two years in prison he met about 30 men who were planning to take up Russia’s offer to prisoners of release if they went to fight in Ukraine, and he had attempted to talk them out of it.

“My statistics aren’t great. From 30 I managed to persuade three not to go. It’s not much, but it’s also not nothing. It’s three people who stayed alive, three people who didn’t kill anyone in Ukraine, three soldiers fewer in Putin’s occupation army,” he said.

Soon after his release, Yashin called for a ceasefire in the conflict, angering some in Ukraine who believe that would only play into Putin’s hands. As someone who spent time in jail over the war, it felt odd to be accused of playing into Putin’s narrative, he said, and the criticism stung. “Ukrainians have the moral right to criticise me, but I do think it’s important to remind people that I am a friend of Ukraine, after all,” he said.

The prospects for the exiled opposition to have much impact on the political agenda in Russia in the near future appear to be slim. Putin’s regime now cracks down on dissent more harshly than ever before, and the opposition’s brightest star, Alexei Navalny, died in prison in February while in a prison swap were in their final stages.

Nevertheless, Yashin described himself as a “political optimist”, but declined to speculate on how an optimistic future scenario might look.

“I am not a political scientist, I try not to think about specific scenarios. I want Russia to change, and for that I try to talk to people and suggest an alternative. I want to explain that Russia can be peaceful, free and happy, and not the thing that Putin is building,” he said.