Mastery Rank 30 achieved - after 7 years 1 month and a few days / 5785h : r/ Warframe
Mastery Rank | WARFRAME Wiki | Fandom
Warframe Mastery Rank Test Guide (Including MR30) | Warframe Wiki
Noob advice : don't do mastery rank test while a warframe update is pending. You won't be able to do it until you restart the client, and if you click to do