You'll likely wanna farm Pluto for that. Pluto Corpus Defense. It starts off as a T3 reward at like a 2% chance, but you have to complete 5 waves, exit, repeat.
Are you talking about the battle pay or final rewards? Cuz if it's the battle pay then 5 orokin cell vs 125k cr and 5 fieldron vs 100k cr and the corpus are still losing
So apparently my computer just had to break when U11 was released and I can't join the event. At least the reward is (hopefully) not event exclusive like the other....
Ran an Alert solo earlier today, a Grineer Extermination, for 14400 credits. Had to kill 70 Level 50-60 Grineer, and I was using the Soma running a Radiation Build.
Every credit was earned, that run. None of the enemies spawned until the last 2 rooms, and hell it was fun. Very hard, as Commanders kept Switch Teleporting me into the crowd, but I returned alive (just)