So my suggestion is what if riot uses the illustrations of the artist in the polycount contest. First of all, this is riot's contest. Secondly, who wouldn't want to have their work plastered into one of the most popular games in this decade. And lastly, it's an nice opportunity for the artist indeed.
Riot should pick some illustrations in the polycount contest for them to use. Not to steal it but to innovate it. Now that riot art's team is focusing on updating VGU/New champ splashes, Icon splashes or other important stuff and specially that there are many VGU's this year and their splash needs some redoing which redoing splashes will be heavily slower. What if riot could just pick some of the most interesting ones in the contest to replace those dated splashes in the game. Not overly transport the whole product as a whole but riot should retouch it to meet current riot's splash standards like they always usually do all the time( like a collaborative work ). After looking the interesting ones, riot should message the artist that their work has been chosen and ask if they like riot to make some adjustments to their work and publish it and replace X champ's outdated splash. And if the X artist agrees, then she can just send her/his source material/Raw files/ PSD file/ like a PSD file(depends on the software used) to Riot HQ so that riot could easily study it and make adjustments to the illustration.
Another thing as to why am suggesting this is because, the artist in these contest always puts their heart/time into creating these awesome illustrations and just submitting this efforted illustrations to a contest is a waste potential when they didn't win( its not primarily waste, don't know how to describe it, but at least they do get some experience but..). So how to award them? why not just use those illustrations riot and you can just credit them like how you credit your artist. And I think if you message those artist, they will be gladly answering a yes because who wouldn't answer a no in multi billionaire company. And it's their opportunity to shine even though some won't win plus you wouldn't need to hire more artist to do some dated splashes. Imagine the slow pace of updating dated splashes to become faster if this will happen.
Some awesome illustrations that needs to be a splash in the polycount contest( some are WIP though, just look in their polycount account to see their pogress):
Note: This are just some examples in the contest which can be a candidate
Hextech Janna by [RaphaelB](http://polycount.com/discussion/196751/riot-2017-art-contest-splash-art-janna-hextech#latest)
Bloodmoon Akali (WIP) by [basedkawaii](http://polycount.com/discussion/196236/riot-creative-contest-2017-blood-moon-akali#latest)
Bilgewater Katarina (WIP) by [MDjeke](http://polycount.com/discussion/194670/riot-2017-art-contest-bilgewater-katarina-splash-rework#latest)
Classic Nidalee (WIP) by [maki](http://polycount.com/discussion/196555/riot-illustration-contest-nidalee-splash-redesign#latest)
Prototype Viktor (WIP) by [kleyvey](http://polycount.com/discussion/196107/riot-creative-contest-2017-illustration-prototype-viktor#latest)
Classic Skarner (WIP) by [EvgeniyaS](http://polycount.com/discussion/194798/riot-2017-art-contest-skarner)
Classic Zyra by IDK, Credit to the artist
TL;DR: Riot should pick some illustrations in the polycount contest for them to use to replace ugly/dated splashes. And to make the artist illustrations not a waste of potential.
PS: You need to read my paragraph unto why i choosed this images and yes, akali, katarina, nidalee, viktor and skarner are not done yet meaning they are **Work In Progress** for those who don't know. I did choose them for you to know that making a splash is not fast and WIPs are the best to represent that.