Ein Sof Lacrima

Ein Sof Lacrima (無限結晶, Mugen Kesshō lit. Without End/Limitless/Infinite Crystals) are theorized to be the evolved forms of Lacrimas in Earthland, capable of promoting the physical capabilities of the user even further than a normal lacrima. Their compositions are described to be at least 90% 'purer' than the average mass produced lacrima and as a result are able to also boost the magical abilities of the user so far to the point of awakening the dormant powers within them. Due to the large boost in power the Ein Sof grants, those that are known to be in their possession are awarded a title specific to their element of lacrima that often becomes infamously known Worldwide, select to only the 6 Ein Sof's that are known to exist. The extreme rarity of the lacrima puts the Ein Sof user in a precarious position, at the risk of being constantly hunted down for either their specific abilities or their extreme rarity that places them at a value of well over 5,000,000,000 Jewels on the Underground trade routes.

The Ein Sof comes as two components; the crest, an extraordinarily resilient piece of metal consistently on the user and the actual lacrima that is stored inside of the user's body, either imbedded within their skin or fused with their blood as magical particles.

Crest
The Crest stands as the remnants of a long lost era, the metal forged by dragon fire and made resistant to any element or substance. Stemming from ancient technology, it is purely designed to be used with the Ein Sof and is unable to be replicated in any feature other than pure appearance. When used correctly, the crest inhibits the 'poison' effect of the lacrima that acts as a parasite, constantly seeking to convert the user's magical energy and in turn their body completely into the specific element of the lacrima. The Crest, color specific to the Ein Sof, serves as a lock and key for the lacrima, where both stand useless without the other, as while also serving as an inhibitor to the negative effects, it is also the only way the Ein Sof's abilities can be used. An Ein Sof without the crest severely deteriorates the user, eventually overloading them with magic to the extent they morph into mindless yet, powerful monsters.

Ein Sof Skill
Ein Sof Lacrima gives their users enhanced physical and magical capabilities however, also gives them an ability known officially as Ein Sof Skill (ESS), which in turn are capable of giving even further abilities to the user. The Ein Sof, an 'enhancer-type' of lacrima, is known to unlock the dormant powers within the user, however is able to go a step further and essentially give birth to previously unknown or lost abilities, as long as the potential exists within the user, most commonly from being a direct descendant of such a user. The ESS is only able to be used when the user is directly bonded to and in contact with the actual lacrima, a loss of contact results in a loss of access to the specific skill.