Blades Initiation : Which Follower Is Good Against Dragons?
I recommend any mage follower, specifically, ice and fire mages. Here's why: There's nothing worse than a kiting dragon, it flies around and then gets you with its fire/ice breath then it lands 100 metres away and you have to run over and by the time you get to it, it flies off to kite you some more.
Mages have a nice distance attack that they'll use on a flying dragon and then they can attack from a distance when it lands.
Archers also have a distance attack but dragons have weaknesses to fire and ice... So go for mages.
There are a bunch of them throughout the game. Try Marcurio, J'zargo, Brelyna Maryon or Onmund.
For a full list of followers and where and how to get them, go here
Skyrim Followers UESP
IMO, I'd suggest:
Janessa because she is good in heavy armor/weapons and is a fierce fighter (Found in The Drunken Huntsman in Whiterun)
Lydia she is also good in heavy armour/weapons and you get to get her out of her home. She has a lot of health and is EASY to get (Given by Jarl Balgruff after your first dragon if fought)
Uthgerd the Unbroken She is a fierce warrior that is ready for a good battle and doesn't settle for less. She is also a mature companion and isn't annoying like Cicero (Found in Bannered Mare in Whiterun)
Hope this helped you pick out your Blades!
I'm an archer, so I found it helps to have a Tank character who can take a beating while you fill the dragon with arrows. The same principle could serve a mage well.
Lydia (you get her as a follower after you kill your first dragon), with good heavy armour, works for me.