So my friend showed me this link and I'm curious at the moment. Is it safe to use? Is it allowed? 
Darkin Hybrid2 votesIt is allowed. In the link you provided shows a screenshot of Riot responding saying that it is allowed as it doesn't hurt the business directly.
Only you and you alone can see the default skin change in game, they are essentially custom skins. So you can go on and use it freely without any risk of a ban.
Who is Taliyah1 votesWrite a support ticket ans ask them directly.
Timethief491 votesIf it allows you to use Riotmade skins without buying them then no its not allowed and will lead to a permaban. If you think about it its nothing but theft.
Potchikir1 votessend a support ticket
