An army and navy who work in the same way as others except their rank titles are upside-down. So people start as full generals and those with the rank of private command armies.
In a deeply unsettled world, much of it anarchistic or ruled by murderous gangs, a group have adopted the armour, weapons and discipline of an army of the distant past.
What if casting magic changed (for a few hours or days depending on the strength of the spell) the colour of the skin of the spellcaster? It could lead sadly to a very racist world to rp in.
The religion believes in reincarnation, but that you will be reborn in the past. People of today are those re-born of tomorrow, with some discarded as trash. The most pure will be eventually reborn in the mythical paradise-like past, where people lived for hundreds, or maybe even thousands of years.
This goes nicely with beliefs into foresight (you know a little about the future because you have been there), but also to many complaints of how things are going always from bad to worse.