Thunderlords skin series: Garen, Olaf, Diana, Kalista, Kayle
The skins should be inspired by the thunder god Thor (we already have Volibear with Thunderlord skin, so you know the drill). Heavy plating,maybe a cape, and first and foremost lightings. Thunderbolt theme .
Garen shoudl be on really heavy plating with a cape, all his attacks would be charged up with electricity and his ulti would be the Demacian Thunder of destruction :D.
Pretty much the same story as Garen, but much less heavy plate armor, he should throw lighning axes, and his E would be a big thunderbolt coming down
Diana would be more like a Valkyrie, and as always she would be throwing out lightning from her Q, lightning orbs from her W etc.
, Okay think about Zeus, he throws lightning from his hands right?, well Kalista in this skins would be doing the exact same thing! Throw out those lightning spears
Pretty much as Diana