The Kolibri was created as a proof of concept design that came from a media streaming program that involved a 'superhero' who fought crime while wearing a power armor suit, and had a jet backpack that was flown by his sidekick, and the two would merge for a flying hero, or separate for multiple attack vectors, or the sidekick would be a spotter for the hero. Kladderadatsch picked up the concept and built a pair of prototypes for the Hanseatic League Technology Fair. The two craft approached the concept of making an air mobile power armor transport with a pilot in it.
The KD 1/7 Kolibri was a conventional design and used a pair of ducted fans for lift, and the pilot sat in a contortionists cockpit. It technically worked, but the fans required a large amount of space to work, were noisy, and in contrast to the popular program, it was an easy target and easily damaged.
The KD 2/11 Kolibri was a more contemporary design and used an internal A-pod and micro-fusion reactor for power. The pilot sits in the Kolibri in a manner similar to a power armor suit, and the user functionally uses their arms and legs to grab the passenger power armor. This version was actually fairly fast, and was reliable, despite being cobbled together out of Kadderadatsch tech components.
Construction of the production model Kolibri was relatively straight forward. Almost all of the components were borrowed from other production vehicles or designs, and were assembled with a modular design process. The A-pod was sourced from the Kladderadatsch 'Werewolf' attack VTOL (which uses three such pods). The power core, cockpit, and control systems are direct from the Flugtag jet suit, used for aerial acrobatics, air rescue, and high altitude operations. The construction of the exoframe and armor follow the basic patterns of light power armor, but use the same materials are aerospace craft for low weight and high strength. This modular construction and readily available tech makes the Kolibri robust and highly customizable.
The production model KD 3.5/13 Kolibri has a high mobility rating, and good speed rating for being only propelled by an A-pod. It is limited to subsonic/helicopter speeds, but it can maintain these even when carrying a large power armor suit. The Kolibri has an hour's endurance when carrying a unit, and three times that when unburdened. Most power armor troopers have the option to link their power source to the Kolibri, giving them more power for flight and maneuvering.
Aftermarket components can dramatically increase the performance of the Kolibri, and while there are tons of options, the most exciting blow-your-hair-back option is fitting a battlemech jump jet to the Kolibri's torso hardpoint. This allows the Kolibri to temporarily lift far heavier objects than the A-pod would allow, or to move to near supersonic speed for a brief amount of time.
The Kolibri has a few serious drawbacks. The vehicle/suit is designed to carry things through the air, so if it is not flying, it is ridiculously awkward to use. When moving on the ground, the Kolibri can barely move at more than a slow shuffle. Its mobility is cut in half when carrying a power armor suit, and this renders it unable to carry out aerial acrobatics, and thus, more vulnerable to anti-air fire. The suit also has thin armor, and is not intended to go into serious combat.
The drawbacks of the Kolibri are easily negated so long as it is used in its support role, and not pressed foolishly into close quarters combat, or combat of any sort. Being A-pod equipped, they are already quiet, and a secured comm channel can make them into excellent spotters and scouts in urban areas.
The most obvious use of the Kolibri is to quickly deliver a single power armor trooper into a situation. This is really impractical, moving armor one trooper at a time, especially when there are larger transports that can move squads or entire platoons of troopers into place at a time. There are very specific cases where the Kolibri truly shines.
Special Armor Deployment - most squads and platoons are made of picked from a list choices of power armor, and within a unit, most are going to be the same. In a rough situation, a Kolibri can bring a specialist power armor trooper that would not be part of a normal unit. This can be as mundane as dropping in a fire support suit, or as specialized as bringing in a stealth suit, sniper suit, or demolitions unit.
Solo Unit Ops - snipers, scout armors, recon armors, commando armors, and other special ops work best with small insertions. A Kolibri with a sneak sheath can appear as a small bird on radar, and fly a commando into position quickly and quietly.
Paramilitary - SWAT, security, and other non-military forces often have access to power armor, but rather specifically do not have access to large VTOL capable power armor transports. These forces typically have to rely on wheeled and tracked vehicles to move their forces, or just go on foot. A group of Kolibri have a relatively low overhead cost compared to a power armor carrier vehicle, and can be used to move high priority units where they are needed.
Emergency Transport - Just as a kolibri can deliver a power armor to a location, the same vehicle can act as a rapid evac. While this is part and parcel with solo missions, it can also function as emergency evac, in a military fashion, or search and rescue, or VIP extraction.
Paradrop - with its lift capacity, a Kolibri can carry a single perimeter pod, a large bundle of arms and supplies, or a cargo container that can hold up to a thousand pounds.
Summary: The core idea behind the Kolibri (German for Hummingbird or something similar) is simple, it is a flying power armor transport with a capacity of one, and would be used as an APC would be used, just reduced to a single trooper in power armor.