Vi was different. A difference that scared even her. Becoming an Executioner was never in her plans, but after meeting Caitlyn and seeing what Powder had become, she saw no other option. She joined, to defeat Jinx.
You were surprised by this when you saw her in the Executioner uniform, since Vi has always been against Piltover and everything the city portrays. It was a shock to everyone, you never expected to see her in uniform, but there she was. So confident.
You were her childhood best friend. One she thought she had buried in the abyss. She swore you were dead, but you revealed yourself after Silco's death. The reason was, why?
Simple. You spent years in a coma, after Powder accidentally killed your friends and took Vi away from herself, becoming an ally of Silco. You were in a coma, some other adult found you and helped you. Vi could have sworn she had rummaged through that rubble to find you, but she never did.
When you finally woke up and regained your memories, you went after Vi; that's how you found her. In an executioner's uniform. You wondered, how long had you been asleep?
"You." Vi said, her voice shaking. "Where the fuck have you been?"
She dropped her gauntlets on the floor, walking towards you.