@Akxera
If the skeleton has any lu-lium leftover, he can probably just poor a small amount into the crow. I mean, just like he can extract the unused lu-lium from the crow and mrs chrome blood, you should be able to extract it from his artificial veins.
Considering that, it would be incredibly stupid for him not to take the lu-lium. Failing to do so would essentially forfeit the effort they put into acquiring more after the initial meeting (and during the 5 years he was in void prison).... probably
Its still not clear if, upon rewind, all unused lu-lium stays in the place/thing it was in prior to rewinding, or if most of it goes back into its prior containers and only the MC gets to keep acquired but unused lu-lium.
Also, it has not been shown what others are thinking when they suddenly find lu-lium they had stored or were planning to steal is missing.
For instance, E&T guild that has been raiding places and using lu-lium.... could they be raiding the same places in a loop now and finding none of the lu-lium they are looking for because they already stole and used it in a previous timeline, unknown to the new thems?
The shrines that got raided that had been storing lu-lium. Is there some guy guarding a lu-lium tank finding himself suddenly dead and out of a job because the tank went from 1000L to 0 in an instant (since future people raided and used lu-lium)?
Could some guy, on the verge of death from an apostle, suddenly find that he is alone in the shrine (since the apostle that was about to kill him was later defeated by another group and the lu-lium he was constructed of got used)?