The Adaptable Combat Equipment, otherwise known as ACE Wear, is created to be fitted to the needs of those wearing them, and them alone. They are designed with a sleek look for more comfortable maneuvers while providing enough bulk and armoring to protect from all small arms fire. It comes equipped with a full body suit, and a helmet that completely conceals the face for more protection, but also feeds combat information in to the user in real-time. Most ACE Wear is a basic black and red color scheme with very simple additions based on the soldier using it, but ACE Wear is modifiable. When not being used, it wraps around the user's wrist and takes on the properties of a simple watch, save for its modified design which is a direct off-shoot of its armor counterpart. It is made of nanocomposite material that binds itself to a single person, and as such, does not work when another person tries to use it. Because of its need to draw on energy to work, it essentially has an energy limited to the one using it. For this reason, when a shadow is put in to ACE Wear, it is effectively consumed by the suit for being a raw source of power, while an Anti-Shadow Weapon would deactivate from the suit draining their Plume of Dusk to the point of deactivation and permanent damage.
The first, and most important feature of ACE is its ability to transform in to an easily concealable watch, and back in to its weaponized form. The second feature is how it hardens based on combat situations, which is important to its ability to adapt. When struck, the inner gel layer and outer nanocomposite layer will harden, making blows that would normally be fatal land with much less intensity and simultaneously creating a cushion between the user and whatever they hit, effectively nullifying all forms of blunt damage such as falling, but not to a degree that it would protect against very powerful Personas. The energy feedback that makes the suit move also feeds some of the energy back in to the user in a more raw state, decomposing it from energy to make a Persona and using it to fuel regular abilities. Since the suit naturally adapts to its surroundings as well, it filters air to make it breathable, has its own oxygen supply, and will eventually equalize temperatures from extreme hot and cold, or even pressures from underwater. It heightens agility, reaction time, strength, and endurance to inhuman degrees for as long as the user can summon their Persona. When a Persona is unable to be manifested, the suit cannot function, and will return to its watch-state.
If the suit is deactivated while somebody is still inside, however, it draws energy from every single part of the body and uses it to harden the user to a state where they cannot move, but they cannot be harmed easily. Damaging the user means breaking the ACE while they are inside of it if the safety protocol activates, and while the suit could be considered perfect, the feedback from having the suit broken and severing the connection from the nervous system could be fatal. Beyond its defensive properties, it also has auxiliary properties, such as energy feeding to another ACE or in to objects using raw energy absorbed from the user's Persona. They can use this to create a pseudo-electrical charge that can power objects for as long as they're willing to expend their energy doing it. Naturally, the suit feeds real-time information to a user to make sure that they, even if blind, can function enough to fight back or retreat safely. Other functions can be added since the suits are modifiable, but the primary modification of choice is an additional medical rig to heal the body of its wounds on a basic level until medical help is found.
One of the unique things about an ACE is how it binds itself to the person using it. In doing so, the appearance matches to fit their specifications. Originally, it functioned as something of a camouflage suit for all situations, and while it retains this functionality, some just prefer to have it look a specific way. When the camouflage is activated, it effectively renders the suit semi-invisible on most surfaces like actual active camouflage. Otherwise it takes on the appearance most fitting of the user, given that it takes direct information from them when using the Persona as power. As an example, a single ACE might appear as entirely white while not in snowy terrain because of the user's wish for it to appear that way, while another may be a military green on just a whim. This isn't a conscious decision, rather, the ACE automatically assigns color given who is wearing it.
The last aspect of an ACE is how it can be changed to fit the user in any way so they can do combat in any way they desire. Amaya Magatsuchi, having invented the suit, normally modifies the suits basic functions and appearance to make it more effective for the one wearing it. She can streamline the suit so the design has an even sleeker look than before while also giving the wearer more speed in all terrains, or remove internal limiters to increase the effectiveness of enhanced basic parameters such as strength or speed. It can, effectively, be modified an unlimited amount of ways, but there is always a trade-off since the ACE Wear can only have a certain number of aspects at a time, and must drain one for another. The only one known not to drain from any other aspect is turning off pain inhibitors. This frees up a massive amount of energy in the ACE Wear, and it can be spread evenly amongst other aspects of the suit, but turning off pain inhibitors means that the user will be in constant pain while using their ACE since it's feeding from their Persona to activate itself. There are both dangers, and mundane modifications, but the primary goal of ACE is to achieve a balance for fighting shadows while giving specific users an edge and the ability to choose how they fight.