Using the best build for Rappa in Honkai: Star Rail can significantly improve the characters performance on the field, upgrading the amount of damage she can deal, and how well she can contribute to breaking enemies Weaknesses. Rappa is a new 5-star Imaginary character on the Path of the Erudition, meaning she is a specialist in targeting multiple opponents at once rather than directing all her damage efforts onto a single target. Several of the Rappa leaks in Honkai: Star Rail 2.6 were later confirmed by developer HoYoverse, showing she is best used as a main DPS in team comps.

https://screenrant.com/honkai-star-rail-rappa-builds-team-comps-relics/