How good are you with your favorite frame? This question is the basis of this idea and it is geared for newer player to introduce them to the concept of forma. When I started playing I had no idea what forma was or what it did; recently a friend of mine hit a level wall and I had to explain to him that he should add forma to increase his character's power. Once he did he overcame the wall.
So the basic premise of the idea is this: once a player hits the max rank for the first time on a warframe, they will unlock a special mastery mission that rewards forma.
The mission would be accessible via the codex. The lore behind it is Ortis is reconstructing his old memories and these are ancient memories of the particular waframe during the days of the old war or just after it. These solo missions limit players to the selected warframe with the warframe's signature weapons with no mods equipped and preselected gear items (3 ammo, energy and health pizzas). The mission doesn't have to be elaborate but it should be something that relates to the warframe's specialty.
A few examples.
Ash = exterminate post-war grineer
Excalibur = survival against sentients
Frost = Defense against post-war grineer.
Inaros = escort/defense against orokin in Mars.
Gauss = in an open mission map like the Plains of Eidolon, Gauss must fight complete 3 Rescue bounty missions under a time limit against post-war grineers.
Limbo = sabotage mission
Loki = spy mission against orokin on Lua.
Mirage = survival against sentients.
These are just a few examples.
The overall purpose is to enhance the new player experience and provide a glimpse into the lore of warframe nothing super elaborate - they can bounce between during, pre or post old war and be as simple as receiving orders to do X from a lore-based NPC. For example: Frost receives orders from the Lotus to protect a pod from post-war grineers. The pod will be transported to the void. Upon completion, the Lotus could inform you that your sacrifice helped save the future of the Tenno. Upon completing the New Dream quest players can make the connection that it was the operator/themselves that they saved or; It doesn't really tie to the overall lore and it is simply a short glimpse of the warframes function like Gauss. He receives a frantic call for help rescue civilians from post-war grineers. Similar to how Inaros protected civilians from the Orokin...or... he has to exterminate sentients with a certain time limit. So long as the mission emphasis the warframes abilities.
Upon completing the mastery mission for the first time, players are rewarded with forma. Reward screen will be a codex entry explaining what forma is and purpose. These mastery missions have no other reward drops (resource, mods, etc.) besides orbs, ammo etc.
Once you complete the mission for the first time, players have the option to repeat the memory mission. The missions will now have 3 or 4 tasks, like perform x headshots or complete mission without enemy detection. These should be static tasks based on the memory mission. Completing the tasks these contribute towards achieving a grade upon completing the mission. Upon achieving a grade for the first time player will receive endo or other items (i.e. random relic or Orokin catalyst). Achieving the highest grade players are rewarded with progress to their mastery rank in order to receive the highest grade players must complete all mission objectives and tasks in one run.
Primes and Umbra versions:
Prime and Umbral versions will share the same missions, and will be limited to their signature prime weapons and may have different master tasks on their missions. Now for Primes that do not a primary, secondary or melee weapon will default to one of the never-vaulted primes like the braton, orthos, lex, paris, fang, burston, bronco or the akbronco prime weapons. Why? Because they may require too much of a significant changes to missions since Atlas prime only has a signature melee weapon and no range weapons.