[Genshin Impact] Ruin Serpent (L93) - Guaranteed Units Only
You have some wide-ranging attacks to manage here, but timely reactions will keep you out of any serious trouble.
You'll need the Lumenstone Adjuvant equipped to manage some of the fight mechanics easily. Higher level Adjuvants will simplify things (due to the increased radius of the Adjuvant's cleansing burst), but aren't necessary. The increased energy capacity of higher Adjuvants also won't matter much, since the Adjuvant's energy will be dropped to 2 at the start of the fight.
The Ruin Serpent is able to summon four Oozing Secretions into the arena for later use. It is in your best interest to leave these alone for now, as you can punish the Serpent for summoning them later; just don't blunder into one of the sludge fields while dodging.
When Oozing Secretions are summoned (and during some later moves), luminous ore will be produced near one of the Secretion pools. Destroying this ore will add energy to your Adjuvant. Keep in mind that this ore still has about half the durability of tougher rocks like Crystal Chunks - you'll need a Geo or greatsword user to break these ores in a timely manner.
If the Serpent straightens its body and starts falling, it will sweep an arc in front of itself with its body in an attempt to flatten you. It's stuck in this arc, however, meaning you can run past its grounded tail and punish it from behind.
If the Serpent looks at you, sparks and winds up, it's going to charge at you. Run forward and diagonally, and the charge will either miss you or do minimal harm; alternatively, running close to or past the Serpent before it can start the charge can make it so the Serpent can't reach you while it turns. Don't get complacent once you evade this, however: the Serpent is going to follow up by resurfacing nearby and slamming its drill onto the ground, creating a vast shockwave. You need to either be far away or perform a well-timed dash to stay safe.
When the Serpent burrows outside of the attacks I just mentioned, it's attempting one of two things - pay attention to the shadow left where the Serpent burrowed to find out what it's up to. If the shadow teleports right next to you, you need to quickly run away: the Serpent's going to create a dirt vortex around that location, ending with a powerful strike. Try to hit it with ranged attacks once you're out of suction range; if you get caught in the suction, repeatedly dash in a single direction to get out.
If the Serpent surfaces near the Oozing Secretions, it plans to extract energy from them for an attack. This is the point where you want to use the Adjuvant to take out the Secretions the Serpent is extracting from (and only those - eliminating the others won't do the Serpent any harm). If you destroy them, the Serpent will be staggered if it was extracting from one Secretion, while it'll collapse to the floor for several seconds if it was extracting from two. Keep your Adjuvant's energy up so you can properly handle this when it comes up; a luminous ore may pop up during this time in case you need more Adjuvant energy. If your Adjuvant's energy runs out, you'll have to focus on attacking the cores on the Serpent's body instead, which will be significantly slower.
0:00 - Character Stats
0:16 - The Fight