Sun | Caster | Debuff DPS | Elemental
Keep her fast enough to extend and recycle debuffs instead of chasing a pure glass-cannon setup. From there, move into the Late-game control route once the core stat line is stable.
Muriel feels best once ATK%, Crit Rate, and Crit DMG are online, giving the first rotation a much steadier payoff.
Skill investment is cleanest as Ultimate >= Special >= Basic, with the first cooldown setting the pace for the full rotation.
Lead with the highest-invested cooldown so the opener starts on the strongest possible breakpoint.
Special is usually the next meaningful breakpoint once the opener lands and should carry the mid-cycle payoff.
Use Basic between cooldowns while you keep ATK% and Crit Rate stable on gear.
Budget target is 3 / 6 / 6, with 7 / 8 / 8 as the long-term skill finish.
Start on the Core line with Insight (4pc) + Hit (2pc) and Speed necklace and ATK% ring. Move into the Late-game control route once the baseline is stable.
CoreCore
Insight (4pc) + Hit (2pc) Core keeps SPD on the necklace and ATK% on the ring.Late-game control
Precision (4pc) + Hit (2pc) Late-game control keeps SPD on the necklace and ATK% on the ring.Priorities
Target Stats
Lock Speed necklace and ATK% ring, then stack ATK%, Crit Rate, Crit DMG, and Speed through substats.
Upgrade Path
Journey: Hard
Core line: Lacy and Muriel. Fill the remaining slots with Bunny Frey, Charlotte, and Petra or Naru.
Lacy Core Muriel Core 
Bunny Frey Flex 1 
Charlotte Flex 2 
Petra Flex 3 
Naru Flex 3 Skill Cards
Passive
Muriel's passive matters more once the core stat line is online and the rotation is already stable.
Basic
Use the basic to bridge cooldowns; it should stay behind the two higher-impact skills in upgrade priority.
Special
Special is the next major breakpoint after the opener and usually carries the mid-cycle payoff.
Ultimate
Ultimate anchors the opener and stays at the top of the investment order for this build.
