https://www.polygon.com/2018/6/18/17475070/final-fantasy-14-monster-hunter-world-crossover-level-cap

Capcom and Square Enix’s announcement of a rare crossover event during E3 that would put Monster Hunter: World and Final Fantasy 14 content in each other’s games left some fans disappointed in its implementation. Players looking to join Final Fantasy 14 to fight Monster Hunter big bad Rathalos will need to have hit the level cap of 70 and have completed the game’s Stormblood expansion before they can unlock the fight, according to the game’s website. That could take a couple months of playing, according to a Square Enix representative.

But Final Fantasy 14’s director Naoki Yoshida said he thinks getting to the endgame won’t be too much of a challenge for veteran Monster Hunter players, whom he sees as very experienced.