The effect is still ongoing. But the chronosphere shift is instantaneous.
Those effects may not all require the effect to not be instantaneous, and then again, the effect isn't quite instantaneous since it takes 1d100 days to take effect.
It's instantaneous in the temporal scale just like teleport is instantenous in the physical scale.
The effect happened on the last round and happened to yourself. But the chronosphere shift happened thousands of rounds ago.
The effect ended a round ago and went on for 1d100 days. If it counts as instantaneous, then as far as the character affected is concerned the effect happened the previous round.
Saying that effect durations are based on the character's perception is a massive broken can of worms and you don't need chronospheres at all to break it in a million pieces. You could just go "lalalala, man I'm bored, time's passing super slow for me, so my temporary buffs last forever from my perspective!" or "lalala time goes so fast, hey that stun already wore out from my perspective!".
If the temporal shift happened at 12 pm of Saturday 1st of March, it happened at 12 pm of saturday 1st of March, and a character temporally displaced to 12pm of the 29th of March is now 28x24x60x10 rounds after.
The only ability I remember that may go through both of those is Erase History from someone staying behind. But activating a superweapon is a fullround+standard action which is beyond Erase History's inherent limits.
Coincidentally, it was the first effect that came to mind when I read Chronosphere. Activating the superweapon is not a fullround+standard action, however.
It is a full round action to set it up. And then it is a standard action to activate. You only need to undo the activation. The character that stays behind and the one that goes into the future can also be the same character.
Clarified that it counts as a fullround+standard actions for effects that care about it.
-You can't just reverse the "bad" effect of going to the future, you would also be reversing the "good" effect of witnessing the future. So you could get somebody back, but since they never went to the future, they know nothing about it.
So after something has been erased from the past, nobody including the eraser remembers what was erased? It could seem that since it never happened, he likewise never erased it, which also should give him back the action used to erase the thing since he never erased it and it is still the current round, but that isn't the case as it does not reverse everything that happened in reaction to the erased thing, only the effect of the thing itself. So the action used to erase is still lost.
For example, a scholar takes a move action and goes into a trapped room. He triggers a trap on the way and a poisoned arrow ends up sticking out of his arse. Worse, the door shuts down behind him and the room starts to fill with water. Scholar decides that "hey, maybe this was a bad idea" and erases the move action he took to go into that room. First thing he does once he is back in the hall before that room? He goes back into that room since he forgot he erased the move and what happened on the way. Enter perpetual loop.
But since only the move action is undone, the only thing that changes is the movement of the scholar, so he is back into the hall but the door in front of him is shut and the room filling with water and he is still poisoned and hurt by that arrow. He could perhaps had undone the trap's action to shoot the poisoned arrow or that other trap's action of shutting the door and flooding the place, but although those happened because he moved there in the first place, only the movement is undone so he doesn't get to undo the effects of everyone's action in one go. Replace the trap by some dude activating them if trap actions cannot be undone. But he'll remember going there and that it was a terrible idea.
That example is already wrong because traps don't take actions in the first place, that with not being creatures and stuff. Otherwise you could undo the sun's own movement.
And yes, if you did undo the movement, the trap wouldn't have triggered and the scholar won't have a poisoned ass. The maneuver even mentions "all evidence mysteriously vanishes" and "Damage inflicted is healed, status effects are removed, creatures return to their previous positions. " The reason it doesn't end in a perpetual loop are two:
-Time is still passing. So if the scholar finds themselves back staring at the door and don't remember anything, they should start getting suspicious that door is bad news.
-Butterfly effect. After enough loops, the scholar is bound to just go "don't feel like going through that door now" and pick something else.
If you retain full knowledge from erased actions, that's a lot more prone to abuse if you ask me.
Not to mention the headache of figuring out what gets cherry-pickling reversed or not. What if the scholar in your example had dropped a bomb inside or something? What if they were using some ability of their own that triggers while moving?
Likewise, undoing the chronosphere's activation returns the character back in the present but doesn't cancel everything that happened in that alternate dimension where some bloke appeared, drank his ass off with his friends and mysteriously disappeared.
The player can't actually act until their turn in the time sequence arrives, which will be days of in-game time.
Past-Old History doesn't mind that detail. Only that he was there and nobody in the present has any proof to the contrary that he got to do stuff in that past-future.
Except it's not the past. It's the future, and the maneuver specifically mentions it only works for actions that could be taken in the past. Even from the character's own perspective what will happen in a bunch of days is the future.
Just like somebody affected by Time Hop simply doesn't get to act until the turn timer catches up with them. I made it a time scale of days so the party can just timeskip a month or so. Not the end of the world. Longer times have been spent finding resources for ressurecting somebody when nobody on the party can do it.
Time Hop however clearly states that the affected character is gone and reappears when the power ends. It has a duration. If you want this to be instantaneous those affected aren't simply waiting for the 1d100 days to go by but instantly act in their own timeline 1d100 days later.
That would be a bit hard since first the rest of the party need to decide what to do for the next 1d100 days to know what the character sent to the future now knows.
If the duration is 1d100 days, it could indeed works as Time Hop though it should keep the same kind of clarification as to what exactly happens mechanically. The buffs of the affected character are on pause during the temporal journey and do not expire or similar.
Well since it's not a duration but a time displacement, there's no need. The character was at time A. Now they're at time B. Just like teleport moves you from place A to place B.
But as for spending time to resurrect people and such, 1d100 days of game time can pretty much mean game over. Just in our campaign we've spent about 2 game days over several years. How long is a player on the bench for 1d100 days? He's just rolling a new character and that's that. By the time the character is back in the present the player will probably have entirely forgotten about it. If the player is still alive.
Any character who can't at least lay low and survive by themselves for some days had no business adventuring in the first place and should indeed be retired.
Anyway reviewing the campaign so far, the only chances it could've happened to the party were in the battle outside the dome and outside the colony ship where the only mecha-less people were fighting for only 1-2. And they have great saves.
Anyway. All that to say that any time-based effect going beyond X-Y rounds is probably not such a good idea. Minutes or a day at best and that would be pretty darn epic.
Even Mass Time Hop affects only the willing. And isn't available starting level 1.
Being chopped to pieces and remains burned is available at level 1. You don't see anyone complaing how hard it's to get back from that at that level, right?
But ok, reducing it to minutes is a good compromise.
