Boss Fighting - Am I prepared?

So I'll admit I took an adventure map and stole all the goodies to do this, but hey, I really needed a boost.

I have shadow armour, a fiery greatsword, a molten bow with quite a few arrows, a molten pickaxe and 200+ health. Will this be enough to take on the bosses? Any advice on how to defeat them? I've tried before but I kept failing...

Please help! :)