Weapon Name and type: Earthly Tether v.3.2- quantum magical harmonic resonance device
Physical description: Fairly small, comparable in design and appearance to two opalescent crystal (most closely resembling fire opal, but with a constant active play of colors, not only generated via reflection and refraction, but by the magically infused crystals themselves) rings fused together in the form of an eight or the infinity symbol- with the seemingly impossible quirk of retaining this appearance and apparent orientation from any viewing angle, including those of multiple observers simultaneously.
Description: The second iteration of the third variant of 'Earthly Tethers', devices which were first successfully created via 'quantum alchemy' (aka as 'transcendence alchemy') in the Kingdom of Aenglisse almost a hundred years ago- enabling them to effectively summon sufficiently powerful magically endowed people from other worlds, with these harmonic quantum resonance devices serving the purpose of anchoring these summoned individuals to their own plane of existence (being implanted within them by necessity during the summoning process). These first-generation 'Earthly Tether' devices, however, were extremely power-hungry and finicky; swiftly draining the summoned individuals of their magical potency, mental stability and physical vitality, leading to their premature deaths in relatively short order.
These issues were all largely fixed in the second-generation 'Earthly Tethers', which also had an added function to actually increase the ambient magic in their vicinity (fuelled via a constant inflow drawn from multiple planes of existence simultaneously), and exponentially boosted the summoned individuals' magical potency and physical vitality as a result; however, these resulted in the summoned individuals (summoned to fight for the kingdom, and provide critical support, against a militarily superior foreign invasion force) developing hero/god complexes, and after the victorious conclusion of said war, they went on a rampage- killing the previous dynasty's royal family, and massacring hundreds of thousands, before finally being defeated and ousted from the domain once more. And as a result of this, the third variant of 'Earthly Tethers' was commissioned and designed, to prevent any such debacles from happening again.
The second iteration of the third variant of 'Earthly Tether' tentatively re-instates the exponential magical boost capability. But as with all v.3 designs, it's also connected via an unbreakable link to a control interface, whereby this function can be activated or deactivated at will on an individual basis. And along with this capability, the reverse function was also added as an option; effectively replicating the exponential magical drain effect seen with the first generation Earthly Tether devices, but deliberately, and far more effectively, rendering them capable of acting rapidly enough to kill most summoned individuals within the matter of only a few days. This, however, is only employed as a control method, rather than in a lethal capacity- with the Earthly Tether v.3 devices employing a far more effective and fast-acting method of last-resort. All have built-in kill-switches, with the linked control interface allowing the controller (aka the 'Guild Master') to initiate a sequence which reverses their original designed function- destabilizing rather than stabilizing the summoned individual's continued existence on that plane of existence, and thereby causing the targeted individual to violently spontaneously explode...