You're going to want a Flamethrower.
Terraria Community Forums
nobody anymore
berberborscing
Not beaten Prime yet. Thinking about best repeater available + Jesters Arrows
Baconfry
Aww, come on, you need Fright for that. Jester's Arrows and the best ore repeater you can get. You get to use an Archery Potion for this battle, works real nice.
DestroyerArcher
What baconfry said. If possible, full set of Palladium armor is nice to have.
MiltVala
And if you know what your doing, you can pull this off (done by Suweeka)
DestroyerArcher
wow umg how duz one pull it off with a hallo repeater if it's post mech?
MiltVala
It can also be done with titanium, takes a tiny bit more time according to oni.
nobody anymore
Prime is 1000x easier @the people complaining about Fright Souls
Bucket
Explosive bullets work wonders.
berberborscing
No kidding. I made 10,000+ early hardmode and it made the Minishark capable of damage 