: invasion, or did he travel back in time here? If the latter, why is he
: begging Leo to help him build a time machine? Did he not take the time
: machine back with him? I’m leaning on this being fan-fiction based on the
: history in the M2 terminals from when he left Lh’owon, so this may be the
: first time he’s attempting to make a time machine.
: ...
: Did something that Leo created enable S’bhuth to come back in time, but just
: as a one-off, and perhaps S’bhuth actually needed something more, a
: different machine, to get back, or to wherever/whenever else he needed to
: be?
If you travel to the past before your *portable* time machine was built, it ceases to exist as soon as you "land" and you'd need to build another one to get back.
A permanent time machine at the starting point would either automatically return you after a delay or create a single use return module at the landing site.