Dratini is unlisted on the Viability Rankings and has trouble against metagame threats like Shellder and Snubbull. I guess you could pull Marvel Scale shenanigans if you really need a burn absorber, but just use a good Pokemon like Growlithe-Hisui instead.
Dratini is C-rank on the (likely outdated) Gen 6 Viability Rankings, which is the first place I could find it. You probably shouldn't be using Dratini in serious competitive play.
