Rathuum is a
Defeating Kela De Thaym will unlock a final Rathuum node in which players must hold out for as long as possible and get as many kills as possible before they all die. Players must get at least 25 kills to qualify for the reward; an Orokin Reactor.
Arena is a game mode in which players must defeat special enemies on modified Conclave maps until a certain number of enemies have been defeated. Tenno don’t need to extract and the mission ends only with their victory or defeat.
The Grineer, for example, like to use armor and are typically weak to Puncture, Corrosive, Viral, or Radiation damage. The Corpus, on the other hand, rely heavily on shields and are vulnerable to magnetic, impact, cold, toxin, or viral damage. Afflicted are weak to Slam, Heat, Gas, Corrosive, or Blast attacks.
Sedna is accessible by defeating the ghost in Sedna Crossing on Pluto after completing the required tasks. Saryn Warframe can be purchased.
Endo is a very important resource in Warframe and is used to update all the different mods you can find. Finding small amounts of Endo is fairly easy as it drops from enemies throughout the solar system and can even be obtained as a reward for various missions.
You can level your Warframes and weapons multiple times, and each level will increase the stats of your gear. Higher levels also increase the mod capacities of your weapons and Warframes, especially when you’ve reached the level max of 30.