How did you become Rioters? As someone who's looking to enter the same world as you guys I want to know what led you to where you are.
Back in the day all the art leads had their emails posted on the official Riot website - I dropped an email to the animation lead asking if he wanted to have lunch and talk animation. He liked my attitude and despite my lack of experience got me in for an interview, I got turned down, worked hard getting better at animation for a year staying in casual contact getting feedback on my craft progress until I got invited back and passed that interview.
Start adding people on social media who do the jobs you want. Making those connections, even if fairly casual, can go a long way!