Okay okay so I don't draw fanart very often... but sometimes one must in the name of expressing all the love possible to their favorite game.

The 4H model has even less combat skill than the 9S model, only able to wield small swords and spears. They are also unaccompanied by any kind of pod, So they have no ranged damage capabilities beyond throwing their spears, which leaves them defenseless for a few seconds. No, 4H units excel specifically at their ability to revert physical damage done to allied units, even in the heat of battle. This includes the basic hacking abilities needed to address Logic Viruses, meaning they can also hack robot lifeforms, but need to be in physical contact with them in order to do so, making the technique combined with their lack of self-defense abilities fairly useless in combat scenarios.

After their original testing period, they were deemed to be to weak to be of any use on the battlefield, and their implementation had the unfortunate side-effect of other more combat-focused models prioritizing the safety of their supporting 4H model over the mission. As such, their line was terminated and the technology used in their creation was used to create the standard-issue healing items given to YoRHa units. Some of their A.I. was also included in the Auto-Heal, Deadly-Heal, and Offensive-Heal chips. Reports have cited complaints by those chip users of hearing unknown, pained voices in their heads upon the chip becoming active, but these reports have not been confirmed.