Manato

Manato's signature. Provides HP and Fire DMG, plus CRIT Rate when losing HP — directly synergises with his kit which revolves around HP management. Best at S5; S1 is still his best A-rank option.

Banyue's signature. Good HP and CRIT Rate stats. The up to 18% Fire Sheer DMG is locked behind EX Special use, which Manato doesn't do often — typical uptime is 1 stack (9%) mainly during stun.

Yi Xuan's signature. Massive Base ATK, HP%, and CRIT Rate passively. The Ether DMG buffs are wasted on Manato, but the raw stats can outperform Grill O'Wisp at S1.

Large Sheer Force buff stacking up to 3 times from Chain Attacks and Ultimates. Scales well with Manato's HP and stun-window damage, but marginal gains over Puzzle Sphere given how hard it is to obtain.

Fully craftable. Significant CRIT DMG and EX Special DMG vs targets under 50% HP. Performs worse in Deadly Assault but perfectly suitable for all Rupture damage dealers in standard content.