Metaphor: ReFantazio

Story-related, cannot miss.

When you get to June 12th, you’ll be thrown into the meat of the game, with a target to take down and an objective to complete before June 21st. This quest is known as the Necromancer Takedown main mission, and sees you head into the Mausoleum and through the Regalith Grand Cathedral to its roof, where you’ll face off against Zorba, the necromancer.

Simply stop Zorba in the Necromancer Takedown mission, and then complete the Thwart Zorba’s Plan operation straight after it, and you’ll have completed the Regalith Grand Central dungeon and this achievement will unlock.

Remember, you need to finish it before June 21st or risk a game over. I will say leave 2 days, as it’s incredibly difficult to do it on one run (due to SP management). If you can get to Zorba though (around level 14/15) you should be good to go back to the entrance and come in with full HP & SP. Your HP & SP will not refill before the Zorba fight, but it will before the next boss fight after. Good luck!