In this instance, players may also utilize Tingyun; however, they will need to choose who to buff based on the situation at hand, since both Luka and Serval can essentially benefit from her buffs.

Source: https://gamerant.com/honkai-star-rail-luka-team-comp-composition-guide-best-character-pair/

Serval can also apply DoTs on all enemies she hits with her Skill with a 100% chance, adding more to her overall damage.

Source: https://gamerant.com/honkai-star-rail-hsr-4-star-characters-rank-tier-list-best/

Serval is the trial character for the Welterweight tournament.

Source: https://screenrant.com/honkai-star-rail-boulder-town-super-league-tips/