In the summer of 2014, Oleg joined the 25th Separate Motorized Infantry Battalion "Kyivska Rus". This unit was originally formed as a ground defense unit, several hundred Maidan residents became its backbone. Oleg was selected for the intelligence platoon - for his experience and skills. Selection for the platoon was conducted personally by the commander, only through an interview. He liked Oleg for his responsibility, intelligence, and creative approach. Mathematical abilities were also needed - to calculate artillery coordinates.

During preparation and coordination, the boys received callsigns. Oleg received the call sign "Shaman" for the fact that he could fix anything - "shamanize", and the commander joked that the Shaman had two tambourines - one on his shoulders (head), and the other was his tablet, which he used to receive information
"Well, the Shaman will come and hit the tambourine," said the commander. He tried to keep the Shaman close to him, expecting to eventually raise him into a worthy replacement for himself.

In addition, Oleg found in his commander a very close senior friend who could help with advice on some purely everyday issues, give some advice from life experience. The relationship between them was more like the relationship between father and son. The commander remembers how he led Oleg into the first battle. They had just arrived, and the situation was tense, it was necessary to go to battle. "Are you sure you're ready to fight?" - asked the commander. The shaman replied that he was absolutely sure that he was not saving.

Kombat later mentioned that there are few people as reliable as Shaman in life. "Guys, we have to be there" - "Combat, we're already there!" Battles, combat shifts, special operations - evacuation of the wounded and evacuation of civilians, raids, deep intelligence, as well as more subtle work - interrogations and intelligence gathering - Shaman was everywhere.

Died during a mortar shelling of the checkpoint of the Armed Forces of Ukraine in Debaltseve.

Awarded the "For Exemplary Service" Award and the Order for Courage, 3rd class

A street in his native village is named after him... since 2015 there is a street named after Oleg Lytvyn!