I feel like that's more of an option to get after getting kullervo and his gun. Cause after that, if you ever encounter him and get the new resource after defeating him. You'll just have extra of it. I think it's a nice small source of credit farming passively. Not the most effecient, but not terrible?
Warframe Assassination Nodes
I just had an appreciation for today's sortie. When fighting the jackal, you have to parazon mercy kill it. There's this cool animation sequence and I feel like this is how other assassination quests should end. It's a shame that you can only parazon kill the jackal and exploiter orb iirc. I'm aware about mercy killing/finishers for normal enemies, but that's only for your eyes. I think it would be nice if other assassination bosses were killed similarly.
Yeah you don't have to do the boosted mission as the other person said. There's a whole process to fighting sisters/liches which you should probably read up on, or watch videos on before you decide to tackle them. It's a bit confusing at first.