Welcome Tenno, here you are going to find all the information you need to beat the Eidolon Vomvalyst in Planes of Eidolon.
Confrontation: Eidolon Vomvalyst
Before the fight against these enemies you need to know that they will be invincible if you don’t have the firepower of your Operator, something you don’t get until you have completed the Quests “Saya’s Vigil” and “The War Within”.
Once you are able to use your Operator and you have your first AMP (the modular weapons for your Operator), the combat will be divided in two stages:
Rewards: Eidolon Vomvalyst
The main reward you can get from the Eidolon Vomvalyst are Intact Sentient Cores, which can be used to increase your Standing with the Quills Faction.
As always, we hope this information is useful and helps you in your development as a Warframe players. If you see a mistake or missing information let us know through the comments below.
Good luck Tenno.