Board Thread:Questions and Answers/@comment-203.81.206.232-20150501220331/@comment-26044650-20150502013613

What I meant is, if you are Invinicble to obstacles you won't accidentally fail the challenge by bumping into obstacles. Using Muscle Cookie and Muay Thai Cookie with 70% Invinicible to Obstacles will take care of that, as Muscle Cookie has 75% Invinibility while Muay Thai has 50%. With the random boost in place they will be completely invinicible which means one less thing for you to worry about.

The Slower Energy Drain you can use through treasures will ensure that you will last longer, seeing how you have to run for 400 seconds. The Enchanted Locket would give you the Energy you need to meet the 400 seconds goal.

I'd go with Muscle Cookie + Muay Thai Cookie with treasures that has Slower Energy Drain and Revives, such as Devilish Revival Grape Juice, Supremely Yummy Monster Muffin or Specially made Flaming Cocktail. There's no need for treasures that gives Magnetic Aura either - your goal is to survive for 400 seconds, after all. Use a pet that gives you Energy, such as the Enchanted Locket. Oh, and toss on the 70% Invincibility to Obstacles Random Boost.

400 seconds is sadly nothing. There is a challange where you need to not hit obstacles for 1,000 seconds.