Delirium says:
... sprint to the mysterious portal she spotted earlier ...
Sure, you can find it again.
Delirium says:
... picking 'you give into your base nature and mark corruption' for her escape a situation? ...
I was looking at the options, and none of the other ones really fit, or are desirable (the only
thing you could leave behind is your phone, and that would cripple you too much to still be a success).
You could also leave your companions behind, that will be pretty unrighteous, but do we want to go that route? Fit as you are, they can both probably outrun you with their supernatural abilities, so that would need to be pretty deliberate.
Delirium says:
... require to do something 'unrighteous' to go past it ...
This would be in addition to, and bigger than, taking a Corruption from Escape.
If you have any ideas of what it might cost you, I am listening... else the price may come to bear later.
On an unrelated topic: If you took another Corruption as part of opening the portal, what Advance would you take?