Describe the feature you'd like to see implemented:
Regeneration destroys enemies close to you, and knocks them back otherwise. It also forces camera and stops all movement. That may need to be undone to make this work, or atleast in certain situations. or have a button that lets you do this.

Combat Regeneration/"Love from gallifrey, Boys!"
Basically to do like the 11th doctor went out and projected the streams of his regen to strike down dalek fighters and then erupt and destroy the big ship above him. Basically weaponize how the streams of energy from a regeneration seem to get focused and fly further if channeled/pointed, sometimes inadvertently, like the several times the poor tardis has been nuked.

What if you made it that when your hands are glowing while in a regenerative state you can use an empty hand and shift rightclick to regenerate and fire a long stream of energy from your hand that you can sweep around from first person.
Mobs that get caught in a regen energy stream you're firing take magic damage constantly and based on max allowed range and proximity to blocks the streams can dig through blocks in a plus shape if focused and cause small damaging fire explosions. block breaking can be turned off and instead just keep the explosions and fire leaving.

The stream counts as your own damage, like a magic spell from a magic mod etc so it will cause items to drop and if you kill something the death message could be "Target was fried by User's Regenerative Streams", "Target was given love from gallifrey from user".

Using your regeneration in this way however is still similar to triggering a regeneration normally and only can be held for up to 10-15 seconds (duration of a normal regen, but you have semi-control to point the beams), and after the time of you casting your beams around it will trigger a short un-delayable grace period that after the 2 minute delay to shine the hands is up and the glow concludes you'll instantly change in a short bright flash into your next incarnation, like how 11th is returned to his normal state, but still turns into 12 after his monologue with Clara etc later on.

Hand containers and Metacrisis_
This could also be one of two ways to trigger a hand sync. Either using the right button on it nearby which is semi-unclear on how to do until I experimented a bit earlier to figure it out. or focus your beams into it, to instead stop yourself changing. If you focus atleast several seconds of energy into the container the container will become "energized" and you'll retain your form like when 10 did it. Syncing to the hand with the button press during a normal regeneration would also cause this effect.

What this now energized hand container would be used for is that in multiplayer if someone else rightclicks the energized hand container they can cause a metacrisis of you and them. They take on the trait of the regeneration, keep their own skin and gain a regeneration and the container and hand is destroyed, replaced with a companion mob in the skin of the hand's original owner.

The Metacrisis mob
Limitations of minecraft, this would be a mob who you can give items to and has an inventory etc who can follow you around and fight with you, or you can just let them roam the area. They don't do waiting though. it's either "help me" or "not following, so gonna do my own thing and walk around".

Something you could fiddle with is maybe letting you turn them into humanoid villagers of sorts and so they can live around a village and act like one, or like an iron golem doing it's guard duties, but aren't cowardly and will fight mobs who are targetting others, but can be talked to to get them to come with, or to trade with them as they go about living their life there. No regens on the metacrisis players though. Possibly take some cues from Minecraft comes alive, or let them be compatible? ;) could be a nice piece of content for servers.

Regenerate Others
Finally, theres that scene where doc heals river song's wrist with what I guess is residual regeneration energy from himself despite not having enough for a full regen until the time lords "give him more juice" in the scene I referenced for the laser hands stuff.
What if you let the regeneration button while healthy and not in a grace period to allow you to glow your hands temporarily and then rightclick other players or mobs to heal them using some of your hunger bar to do it. If you want to get over technical and canon with it you'd probably need a regeneration energy bar in your regeneration window and some limit to how often you can heal people related to it before you cut into your later regenerations.
Alternatively you can just put a limit per regeneration to the amount of times you can do it. Could be useful for something like an ultra hardcore or a pack without natural regen. you never know.

anyways, sorry, another wall of suggestions. :V

Additional context

https://www.youtube.com/watch?v=6AxCoMbiZfk

edit: edited in section headings between the subjects so it's not a wall, as you requested.

copied to discord.