[Model] Tornado-like column

[Razengami]

hello, in my rpg i have a spell for which i need some sort of tornado... id like the tornado to be like a column, with no sharp top at the bottom.. and not too large, but very high (long)
and also the bottom of the column to be a bit more large than the rest of it

i hope i explained well enough because my english is not very good.. ask questions if my explanations are not good enough

thanks in advance!