I hope this is straight forward. I have spawned a model:

All I need to do now is apply the tornado.wdl file to the tornado.mdl file, I'm just not sure which function to use.

there must be some functions/actions in your tornada.wdl, include the tornada.wdl in your file(the file that you are using ent_create in it)

then apply the main tornada function instead of NULL:

ent_create("tornado.mdl",vector(random(1000000),random(1000000),0),TornadaFunctionNameGoesHere);