Operation: Mechagon is in the 8.2 patch for Battle for Azeroth and it has a hidden mode. It has a so-called hardmode, but triggering it is not easy.
You trigger the hardmode by defeating the first 3 bosses. On the map and above your heads you can see the Aerial Oppression Unit patrolling there. The unit will then fly over a boss and you have to defeat him first and repeat this until boss number 3.
When you've done it you'll get the new boss no. 4, the Tank Buster MK2. It not only has more life and damage available, but also a few other surprises.
When you defeat the final boss: "King Mechagon", you get the mount aerial unit R-21/X. The item level is 415+ and you have a chance at the item: War Forged, Titanium Forged and Socketed items.
You will then get the achievement "Do still damage and nobody explodes". One random player gets an Azerite helmet with item level 430 and another gets the aerial unit R-21/X. Let's say you manage the complete raid without dying then you get the success "Death Command" and the fourth rank of the essence "Vision of Perfection".
With our pro boosting service we'll get the hardmode done fast and you can experience the special Easter Eggs of the game.