So this just came up in another thread, but apparently you can’t burn your last non-Mash servant. This means that every single account must at all times have at least two servants (there may be a short moment in the tutorial where you only have Mash, but I’m not counting that). I’m pretty sure that this is because you need to enter every quest with a full front line (Mash, your other last servant, and a support), so if you didn’t have any SQ or FP, you could mistakenly softlock yourself if you left yourself with only Mash.
This got me thinking, is there a way to softlock yourself?
You can’t enter quests if your servant or CE inventories are full (only one of them needs to be full), so the first thing to do is to fill those, and also fill your second archive. You can still burn or level servants though, so these need to be taken care of too.
If all of your servants/CEs are at their level cap and you can’t ascend them any further, then you can’t use one servant to level another servant. For this reason you also can’t have any grails, as these would allow you to do paliengenesis, which would raise the level cap and allow you to level servants with your other servants. You also need to make sure that all of your servants with dupes are NP5 so you can’t raise their NP levels. Also because of this, you should be filling your servant inventory and second archive, because it’s a lot easier to fill and level these than it is to fill and level your CE inventory.
Burning is more difficult, but I think that if you are at the QP cap of 999,999,999 then you can’t burn anything. This means that you also need to be completely unable to raise any skills or engrave any cards.
You also need to make it so that you can’t summon, because if you get a servant then you can use your other servants to level that servant, then you can burn servants because you’ve used QP, and you can escape the softlock. Because of this you need to make sure that you have 0 tickets, <3 SQ, and either <200 FP, or have your servant inventory be at least 50 over capacity (it might be 100 actually). For this to work, your last inventory slot must also be an EXP card, or a Fou if you’ve max Foued all 499/549 servants, which seems unlikely.
So with this, you can’t enter quests because you have too many servants, you can’t summon because you have no SQ/tickets/FP, you can’t burn any servants because you have too much QP, and you don’t have any way to use your QP.
Is there any way out of this softlock except for simply waiting for your daily login to roll, or by buying SQ?