i should be up for it,considering most of my characters are 25-35,and i'm starting to struggle on adventure mode. time to do that master quest map i keep hearing about!
It's probably smarter if you complete the Adventure Map first before taking on the Master Quest Map. The DLC maps tend to be more difficult than the default content, so you're better off level grinding to make your warriors stronger, and getting hold of all the Adventure Map weapons as well.
You see, you need to collect ALL of the Legend Mode and Adventure Map weapons in order to awaken the Master Sword's skill; the skill is called Evil's Bane, which raises the Master Sword's attack power by 200 points. After Evil's Bane is unlocked, you'll then be able to awaken the Legendary skill from any weapon with a skill that requires you to make 25,000 KOs.
Legendary raises a weapon's attack power to 300, and an additional 30 attack points are added for every star that the weapon has, maxing out at 450.
You'll likely need the aid of those skills for the Master Quest, Twilight, and Termina maps, as there's a reason for why the level cap increased with the release of each new DLC pack.