Originally Posted by
noxybell
They will (assuming Nutaku KH lasts that long), and they did in DMM.
In the future there are Accessories, items that you wear to boost your stats. To obtain the SSR tier, you need to defeat Raid Ragnarok-level boss difficulty in Advent event setting, aka alone. Bosses are hard due to various reasons like inherent characteristic of no rage bar, high atk like guaranteed triple hit for total of 12k damage, massive tank like +50% defense and/or nasty debuffs (skill lock for 3 turns) etc. And there are equally-hard pre-boss mobs that are challenging themselves.