In God Eater, Lenka and Alisa are both apparently "New-Type" God Eaters. Two questions about that:
The weapons utilised by the God Eaters, the God Arc(Jin-ki) are split into new types and old types. New types having the ability to transform between a gun and a sword and can convert the Aragami it eats into energy for more bullets. Old types are just Jin-ki that only has one form, a gun is a gun, a sword is a sword.
New types are called new types cause they use a new type Jin-ki. They are the same as normal God Eaters biologically with no other modifications on them whatsoever. They are made into God Eaters by injecting Oracle cells into them, same as the old types. Its just that they utilise a newer weapon.
The God Eaters that can utilise new Jin-ki are prized as to use the weapon you have to be compatible with a Jin-ki to utilise it and those that are compatible with the new types are rare so they are highly prized due to their higher battle prowess with new type Jin-ki.
God Arcs are mechanical weapons that are infused with Oracle Cells. In short, the God Arc is actually an Aragami itself,with an artificial man-made core called the Artificial CNS. It is currently the only weapon capable of eradicating the Aragami. The God Arc can be temporary boosted by devouring an Aragami.
The God Arc is a complex weapon. As it is an Aragami, it is made of Oracle cells- the only thing that can harm them. The first form of God Arc was in the form of a gun that shot converted Oracle Shots. At first, these guns were no bigger than a pistol, due to the cores being converted coming from Aragami the size of small mammals. However, with these pistols, the God Eaters were able to take down bigger Aragami such as Ogretails. In a process similar to natural evolution, the God Arcs then evolved to the size seen today. Next in development was a God Arc made in the shape of a blade. Typically, blades could not harm Aragami due to the bonds between cells being too strong to unbind. However, with God Arc blades, Oracle Cells are lined up along the blade's edge, which allow the blade to cut the bonds and harm the Aragami.
One clear difference from being a New-Type God Eater is that as the name implies, you wield a New Type God Arc which can be wielded either as a gun or a blade.
What makes someone a New-Type?
There are actually two factors:
They are made into God Eaters by injecting Oracle cells into them, same as the old types.
God Arc Armlet
Gods Eaters control their God Arcs through their armlets, using intravenously injected Bias Factor as a catalyst. In order to wield a God Arc, Oracle Cells must be embedded deep inside a human body and linked to his nerves: it is essential that his genetic makeup be compatible with the God Arc in question.
Compatibility
It [God Arc] is completely linked to its compatible God Eater; if a God Arc is wielded by a non-compatible God Eater, its Oracle cells will begin to devour them. This is a fact that was, at first, without a single exception.
New-Type God Arcs:
These are the newest type of God Arcs, and people who wield them are called New-Type God Eaters. People who are compatible with these God Arcs are quite rare. Unlike the Old-Type God Arcs, these God Arcs can freely transform between Blade Form and Gun form. New-Type God Arcs exhibit superior power as compared to Old-Type God Arcs.
However, the God Arcs with this function seem to have lower rates of compatibility than others, making Old-Type Arcs still feasible.
Source: God Eater Wikia
Why are New-Types so prized? What can they do that "old-types" can't?
(New-Type God Arc) Recently developed by the Fenrir HQ, these God Arcs can instantly switch between close-combat and long-distance attack mode, a flexibility sure to prove invaluable in various scenarios on the battlefield. However, its conditions for compatibility are more stringent than for Old-Type God Arcs, and Matches are quite rare. Because of this, there are still many unknown regarding the New-Type God Arc's effects on human bodies.
Source: Wikia
Development of New-Type God Arcs
Flaws were apparent in the two separate types of God Arc. The blade type Arc could collect Oracle cells for conversion, but could not fire them; conversely, the gun type Arcs could fire the shots, but had no means of collecting Oracle cells short of refills carried with the God Eater. This was fixed with the development of New-Type God Arcs. These weapons had the functions of both blade and gun, and could therefore fulfill a much more flexible role as melee and long-range platforms.
Source: God Eater Wikia
