Who, specifically, can I thank?

I have received Reaper Soraka as a mystery gift, which I am really grateful for. But, rather than just post a general "Thank You" to Riot (though I do thank all of Riot for their generosity with this decision), I would really like to thank the specific person or team that gifted me this skin. I don't know how realistic a request this is, and I know it might be a tad odd, but I feel like Riot has made an effort to make each (non-toxic) player feel individually valued with this present, and I would like to return the favor. If it's possible to find out who sent the gift, I'd love to know.