All Kuva and Tenet weapons require 5 forma to max out
The Kuva Tonkor, the best grenade launcher in the game in my opinion. But I got radiation on mine, and I run it for magnetic damage, and since its already a blast weapon its an explosion of radiation and magnetic damage, two of some of the strongest mixed damage types in the game. So this build in particular does DEEPS!
Plus multishot, which means that per shrapnel chunk that comes off of the round does the amount of damage from the average hit when in a certain radius. But it does have fall off, so if you can do the math on that more power to ya. Hence why I run [Primed Firestorm] on this thing.
Keep in mind that this is how I build MY weapon's an warframe's, they work really well for me, so if you are one of those people that is going to to go into the comments and give me shit is to how I play the game, I will kindly ask you to put a tooth pick under your toenail and kick a wall. JOKINGLY OF COURSE.
If you do decide to follow my builds don't get butthurt if your numbers aren't the same, all the riven's are the ones that "I have rolled" so don't psyche yourself out if you don't get a riven that is a good as the ones in my builds.
Be sure to take a look at my other builds. I also recommend looking at the vault status of all prime variants in the second link below. If you want information on the quests and the requirements, I recommend looking on the actual Warframe website under the game dropbox to look at the warframe profile videos as well as looking at the quest guide and the faction types. Click the third link below if you are interested.
Wiki:
https://warframe.fandom.com/wiki/Prime
Warframe website:
https://www.warframe.com
My Guide for new Players!:
https://docs.google.com/presentation/d/1NDLcIbpVdBX559tW5RVLdmoZ1lNnf_3CsjMLL1KKtco/edit?usp=sharing