The game has a system called SOL3 Phase Level which represents the threat level or difficulty players will encounter when facing enemies and bosses in the world. In this page, we will discuss why is it necessary to raise this level and how you can increase.
Wuthering Waves takes place on the fictional planet of Solaris-3, where the name "SOL3" comes from. The higher the SOL3 Phase Level is, the stronger enemies become while also increasing the quality and rarity of loot dropped. The more challenging versions of bosses in Tacet Fields will be unlocked as well as you increase your SOL3 Phase Level. Defeating them will yield more rewards and higher rarity materials.
Aside from that, your Resonator's (character) will also require SOL3 Phase Levels to ascend them. This will ensure that you have reached your character's bare minimum level and strength to scale properly with the enemy's level increases.
You have to keep increasing your Union Level in order to reach the required levels to increase your SOL3 Phase Level. Union Level is basically the player (account) level, which in turn can be increased by completing quests and various activities in the game. We will discuss this further on a separate page.
After reaching Union Levels 20, 40, and 60, a mandatory special SOL3 Phase Ascension quest will become available. This serves as a trial to test if your characters are strong enough to survive the higher difficulty. You don't need to take this quest immediately but take note that your Union Level will remain capped regardless of how much Union EXP you earn until you finish the Ascension quest.
The Ascension quest is just a combat trial where you have to defeat a certain number of enemies within the time limit. Be warned though since the enemies you'll be facing are a few levels higher than your current level cap at the time. To ensure that you're prepared, take the Ascension quest once you have fully maxed out the highest possible character level and weapons for the phase (Phase 1 at Union LV20 has a level cap of 40). It will also be helpful to add a few levels to your echoes - just remember not to waste your resources in maxing out the levels of blue echoes!
During the actual challenge, you have to pay attention to the team composition. They'll usually have a tankier unit that will take a while to defeat, some DPS, and at least one support unit. Always target their support unit first, then take out the softer DPSes, before finally focusing on the tank. Of course, if you're able to use AoE attacks and get them grouped up, you can save time by quickly defeating them.
So, you managed to clear the Ascension challenge. The first thing you'll notice is that all enemies, even the common ones will have their base level increased. While they will drop better rewards, you might find yourself overwhelmed and underprepared, especially if you haven't farmed enough character ascension materials from the overworld bosses.
Thankfully, the game allows you to adjust your SOL3 Phase rank to lower the difficulty even after you have already cleared the SOL3 Phase Ascension quest. You can do this by opening your menu, then clicking the circular exclamation point (!) at the end of the SOL3 Phase field. You can only adjust your SOL3 Phase rank once every 12 hours. Additionally, you cannot adjust the SOL3 Phase rank higher than what is the highest you have achieved.