So, why is a giant charged tesla ball capable of zapping things doing in the Creeper World world?
Well real quick, I will NOT explain the science behind how this thing works as Vertu has invested so heavily in lightning arc based technology they have exited our own realms of science on Earth AND such science is one of the few held secrets of Vertu which can't be talked about nonchalantly. In short, Vertu is really good at making lightning and tesla based weaponry.

Anyways, the V-Tesla was created in response to hoards of Skimmers encountered by Vertu incursion units. We are talking about waves of over 70 skimmers charging in. Snipers where just too inefficient and unwieldy. The V-Tesla is possibly too good at its role as “a challenge” is important in Vertu's pursuit in constant live testing of science, research, and development. However, 70 skimmers is 70 skimmers. They release Electro Magnetic Pulses, have enough of them and it gets very annoying for sensitive equipment running open data collecting while in service. This makes the V-Tesla an acceptable exception for being too good.

Since the V-Tesla was created in response to tsunamis of skimmers, you will likely not have access to the V-Tesla in most missions. In the event you attempt to summon a V-Tesla via the Summoner and it is unavailable, the Summoner will safely abort after timing out and not transfer the stored Lific while informing you of the V-Tesla's unavailability.

Not much else to say, now when/if you summon it in, be sure to enjoy its effectiveness as it obliterates entire waves with little effort. Just be sure to manage the power consumption of course.