This makes no sense, and you kinda debunked your own reasoning
We see Imu, in a weaker form, able to conjure weapons at will and at ease.
Why would he teleport to elbaf, while coughing up blood mind you, with a weapon already in hand, if it would be a generic weapon he has no attachment to or can just pull out of thin air?
its clear thats a personal weapon he values and fights with as his main weapon, like enel with his rod
@Fujishiro
As far as nika goes we know not enough