One Piece Chapter 539

[Tyreal]

It's nice that Luffy lived, but how is he (or Ivanova) going to take down Magellan?

Best guess is that Luffy will learn to use Haki in order to nullify Magellan's ability. After that they'll break Ace out of prison and Ace (along with most of the other prisoners of Impel Down) will deal with the Marine battleships. In the end Luffy's bounty will go up and he will become even more infamous since he managed to infilltrate Impel Down and free a crap load of prisoners.

Another option for Luffy being able to beat Magellan's ability is that since he has already been exposed to the poisons and been healed he is now immune to Magellan's poison.