Theorymonning is the art of combining creativity with rationality to speculate what would happen if certain Pokémon possessed new traits. Highly popular amongst the Smogon Community, it was no surprise when OU also got its own thread to discuss these theories. So, join me on an exciting journey of some very interesting theories that will definitely leave you with food for thought!
Smogon OU theorymon introduction
Here they see combine new abilities on other Pokemon for an example : Techician Weavile. Or other common things that makes new traits.
Source : upper link