When entering Dungeon Depth 1, there are a few key strategies that you can employ to make your experience smoother and more successful. First and foremost, it's important to focus on your avatar's damage skills and to increase their ability so that you're able to deal more damage. Using a skill that hits all enemies is also a smart move, as this will allow you to clear the stage quickly and efficiently.
If you find yourself struggling during a battle, remember that you can always restart the battle rather than going back to the start of the depth. This can be a useful strategy if you're about to die and want to try again with a different approach.
One powerful Guardian Skill that can be particularly useful is "Judgement Day." To maximize your damage and bounce, try targeting low-health targets whenever possible. This will allow you to deal a significant amount of damage and take out multiple enemies at once.
When facing a healer, the Rogue skill "Blade Breakdancing" can be a great way to take them down. This skill is designed specifically to counter healers and can be a real game-changer in certain situations.
If you're facing a large number of enemies, consider using a mage. The damage from their skill is area damage, which means that you'll be able to hit multiple enemies at once and take them down more quickly.
Finally, to defeat the boss, I recommend using a combination of two guardians and two mages. Bringing plenty of potions to heal your avatars or apostles is also important, as this will help you to stay in the fight longer and deal more damage overall.