There is a new system called the Ancient Scrolls that starts once you beat the final online boss, Gogmazios (NOTE: this is an urgent so it has to be your quest that you beat, not another players). The Elder gives you Scroll #1 and you are asked to decode it. By hunting enough monsters (appears to be a hidden pt. system so all hunts count toward it, but tough G quests seem to decode them faster), some of the letters will appear. Once all the letters appear you hand the scroll back to the Elder and he unlocks a super hard quest.

Scroll 1:

Rare Tigrex

Scroll 2:

Akantor

Scroll 3:

Extreme Selregios

Scroll 4:

‘Super’ Chaos Magala

Scroll 5:

Dara Amadula Subspecies

Scroll 6:

Extreme Rajang

Scroll 7:

Bracchydios Variant (Explosive Bracchy)

Scroll 8:

‘Super’ Gogmazios

Scroll 9:

‘Super’ Ukanlos

Scroll 10:

Crimson Fatalis Variant (Super Hot)

Final Scroll:

Multi-monster quest: Frenzied Tigrex, Super Zinoger + Frenzied Bracchydios, Super Chaos Magala, Extreme Selregios (GOD DAYUM)

I am not sure what you get if anything for finishing that final one, but I bet something. So there you have it, the final super quests and monsters are not unlocked via HR like high rank, but a new system that unlocks as you grind monsters. The more you play the more you can play! :p

Happy Hunting!