Wanted to revive some debate as to what exactly old Stalky is exactly
We know he was essentially an Orokin babysitter as a guard when the empire fell. But that raises the question for one, how is he still alive and for two, how did he learn to fight Tenno?
My theory is he himself is either a Tenno or he is a form of Warframe
I think there’s a possibility after the Tenno killed the Orokin, he either found some way to work the Helminth or just infected himself with the infestation
You could make the argument that he has gone insane, though not necessarily berserk, since he is filled with murderous rage over an event that happened centuries ago and with vigor he’s forgotten who he even is.