Hear Nikola tell more about her experiences in the video above.
Nikola, who comes from the Helsingborg area, went to Ukraine just over three weeks ago to fight as a volunteer soldier - even though he has no connection to the country.
His primary task has been to, together with a group of, among others, two other Swedes, pick up wounded soldiers at the front, says Nikola.
But the last few days the group has been in Butja.
- We needed better here at the moment, says Nikola who tells about mass graves and burnt corpses.
He does not want to go into what he has done in Butja, but SVT has taken pictures that prove that he really is there.
So far he has not participated in any battles.
When we spoke to him before the trip to Ukraine, he told us about how he saw the risk of dying and about how he sees the need to use lethal force himself.