Not quite AL, but I have an Earth Genasi Warlock who 'owes' a power his life (His home village was attacked by Elemental Cultists and he was killed with his family.. only to wake up later unscathed.'
We are playing Princes of the Apocalypse and my DM has let me variate the Fiend Patron to be in this case Ogremoch.. who is the Prince of Earth and the evil taint to it. My character dosnt know this however, he just knows the power isnt good. Whilst Im playing a Pact of the Blade Boon Warlock, my dm had mentioned that If I went Pact of Chain my Imp would of looked more earth like. Dirt and Soil constantly falling off them and they would like a slimy /oily trail behind them.

(Dungeons & Dragons)
Rulebook featuring "high magic" options, including a host of new spells.