Additions to my
already existing suggestions:
6. Light absorber
Like a standard coal-generator, but it absorbs light from glowing substances (Glowstone blocks/dust, redstone dust, Xychorium, neither lava nor torches due to
balancing too high temperature).
7. Solar powerplant
Being highly unefficient just placed somewhere outside, this thing starts rocking when you build bundling lenses above and/or mirrors around, so it can bundle more solar energy, and at the highest levels maybe even starlight, concentrating it into Xynergy pulses (or whatever you are going to call them).
However, due to thermal attrition and ultraviolet radiation, the structures inside may get inert over the time, so the core unit needs to get repaired/replaced and you might want to wipe the lenses and reflectors.
If you want to get really complex, add modular cooling systems for the core and superreflectors/absorbers.
8. Nanites
Oh my, this is going to be complex....
Created in fleets from crystals with carved-in microcircuits and Xychorium, these little things are easily ingestible if applied to some kind of food and modify different attributes, for example act as internal armor, concentrate in Steve's right hand so his punches get more power, act as additional erythrocytes to increase his sprinting speed, or just swim around in his veins, cleansing him from poison, depending on their programming and tools.
The lower tiers might be kind of dangerous, ocassionally harming their host when one of them crashes into an organ or shortening all potion effects, at higher tiers they might get more intelligent and, of course, more powerfull.
Of course they need power, wich is drained from ZPMs (would sure look nice if placeable btw) in the inventory, and if you want to get rid of them, activate a magnet to get them all out via your oral mucosa (might hurt a bit?).
There might also be some to be applied to animals and mobs, maybe some containing a retrovirus replacing the hosts DNA with some other, increasing their circulation for more resource output, or just apply mindcontrol to make friends with creepers and endermen. However, since these guys do not eat that much, you might need to apply them to some special tool with a special module...
9. Meant-to-be lightshow (come on, you know this had to come earlier or later
)
Yeah, not that much of an use, but you might also have wished for some kind of visual effects when playing your musicdiscs, maybe even in special patterns according to the disk played nearby. Eventually the mirror balls and spotlights are even manually programmable for colors and movements.
10. Pulverizers/Dissolvers
Covering the whole spectrum from sonic sound over magnetic waves to gravitational pulses for the pulverizers and leach, (sulphuric maybe?) acid and nanite-emulsion for the dissolvers, there are more than enough ways to upgrade those, whereas the higher the tier the higher the chance of doubling and, maybe, tripling and also finding something else in the ores.
The main differences between pulverizers an dissolvers is that first are easier to obtain and need power, maybe also create byproducts like cobble or gravel, whereas last use resources whilst being more efficient and only output pure minerals.
Even more to come I think.