Be one of the first 100010000 players in your region to defeat Nullaeus in his lair on Tier ?? without any other players in your party, before the release of the next season of delves.
While it is a good change, it doesn't address the main concerns players have with the achievement. The main issue players are seeing with this achievement is how many delve bosses so far have been easier for some specs than others. For instance, Ky'veza was overall easier as a tank or tankier melee spec, being way harder as a caster or squishy spec.
While some players had multiple characters available to complete these as the season started, many players will only upkeep one or a few characters, not having that luxury.
