For a long while I was a Mid main and then in season 10 or 11 or so I decided to swap to ADC because I felt like I had more control over my own performance and had a better chance to carry with/for the team.
I main Caitlyn now but my highest mastery is still Lux.
Haven't been able to play Caitlyn on 13.15 yet, looking forward to trying out the buffs.