Lancer

I don't know, what do you want?

Supportive hardy core with aoe or powerhouse ST that wrecks shit?

Tsundere or possessive mom character in swimsuit?

Need more description.

Flat(ish) is justice, Ereshkigal!!!

Scathach

I prefer Summer Raikou as her damage is much higher.

Both have their good bunch of utility, eresh buffs The HP, defense, NP rate and attack(this attack buff is when she uses her NP) the downside is that she haves the lowest attack of the 5 star lancers, but that is not a problem with her kit and mana burst + 50% battery. Summer raikou is a excellent boss slayer since she haves a star absortion + crit damage skill, a targeteable buster buff that removes debuffs and the charisma of archuria but here it applies to the entire team without any exception, her downside is not having any survivability skill so you better find a way to fix it. Both are extremely good but at the same time they are extremely rare with 2 rate ups both, this is where you decide in either AOE or ST, hope that this helped you.