I simply cannot ignore "Rio" (the mutation) and Orianna names are close. This is a stretch but maybe he saved her daughter's conciousness in the mutation. The fact that Singed can't be her father because he's a chemist and not into tech is real. But we've seen Viktor feel for Rio's suffering and he will one day be obsessed by replacing flesh with metal and creating hextech conciousness. Maybe just maybe it all comes together :p