Not all of these would apply to all tech demons, but this is a varied and generalised spread.
> May need less sleep than other demons.
> May be able to turn some senses on and off.
> Likely to have ports to connect to other tech.
> May have sharper recall if no errors present.
> May be able to transfer memories as files or upload posts directly from their minds, similarly for accessing the internet. This can also open them up to computer viruses though, double-edged sword.
> May have a great affinity for tech that matches them, in more pronounced cases to the extent of being able to make pets of them (does not require the tech to have had intelligence prior).
> Varied types of reactions to electricity possible, many positive and some flustered. Some with more pronounced reactions, like Alastor, make use of specialised wearable ‘surge protectors’ in public to stifle those reactions to avoid being embarrassed in a fight involving electricity. These are discreet fastened armbands typically worn under sleeves.
> Engine-related demons can consume fuel matching their engine type (same true of other fuels/energy sources and the demons matching them) but no guarantee that flavour will be any good.
> In general, if a demon is significantly tech, there’s likely to be some kind of access ports, panels or somesuch somewhere, though this can be quite discreet.
> Many waterproof but not all.
> Self-customisation plausible if parts and skill readily available.
> Some tech demons can be hacked, and must find ways to protect themselves from this.
> it is recommended that tech demons - especially those associated with more sophisticated technology - undergo updates/upgrades on a regular basis for the good of their own health.
Over time, errors and malfunctions can creep in, and it isn’t a good idea to allow this to go unchecked - especially if a tech demon’s technological affinity is in any way connected to their mind. More serious cases of unchecked errors can affect memories and perceptions, cause glitching and loss of time, and if not treated can result in the demon’s identity being lost.
This process is known as obsoletia, and while there are stages at which this can be halted and even reversed by a skilled technician, allowing it to proceed to the final stages results in the demon fading out. Unable to respawn without identity, but not having been slain by angel blade, these souls are thought to drift out of Hell to be reincarnated as someone new.
Though the risks associated with avoiding updates/upgrades aren’t to be trifled with, things aren’t exactly as clear cut as would be ideal. After all, the process involves allowing someone to tinker with one’s mechanisms and potentially software connected to the mind - checking reviews carefully is important to find someone skilled who can actually be trusted to not meddle more than they’re meant to, especially if one has prominent enemies in the technological field.
(Anything obsoletia-related will be tagged obsoletia if it does come up)