I just found out Semiramis last Noble Phantasm. It allows her to create poisons quickly and spread them through the air while making her immune to all poisons. Thus I would like to switch to another servant if that is okay. As her power is currently a big f you to another servant here.
Unless you know what Atalanta's skills do other than "hoping over things in her way" and "confirming the enemy's actions", I'd say either Moedred or Altria :P
Hoping over things in her way, means she can run through obstacles without losing much speed, very useful for an archer. As for confirming the enemy actions, that means you can predict some of the enemy attacks. Meaning you can dodge a bit more, kind of similar to Arturia instincts that allows her to see her own death before it happens.