This post will show you an easy way to unlock the "For The Horde!" Onyx Medal on Gears of War 3 by completing Wave 1 to 50 on Insane

Its actually not that tough, as long as you have

• a few buddies
• a few mutators
• a bit of patience

This video below will show the final wave in action. The mutators on this video are detailed here also.

Use these mutators if you want to beat wave 1 - 50 on Insane difficulty and earn the Onyx medal.

Taken from the video details:

"To complete wave 1 - 50 on insane and unlock the onyx medal, all you have to do is turn the following mutators on.. then play the waves. You wont get as many points but its easy to complete. Easier than 1 - 50 on casual with no mutators!

 
Mutators:
Instagib Melee,
Infinte Ammo
Super Active Reload

The 'super active reload' is the most important, it allows you to kill anything really quickly, pre active a full clip with the lancer and you can kill almost anything with about 4 lancer bullets!

200 kills as a wretch in beast mode to unlock 'super melee' mutator
100 ribbons in combat engineer to unlock 'infinte ammo' mutator
obtain the Bronze Master at Arms medal to unlock the super Active Reload Mutator. Unlock this medal by scoring 100 kills with all five of the starting primary and secondary weapons."

For a full list of medals and their requirements head over to the Seriously 3.0 Boosting thread!