What if for his pact, Gil asked to get into paradise and Nevy asked to get her memories back.
I think that would 100%, without a doubt, lead to a pact failure.
I’m pretty sure Paradise doesn’t exist in a form like Gil is imagining it. The machine that dismembered Prudith was referred to as the ‘gate to paradise’ and Six said that giving the follower inside the ‘perfect body’ (referring to immortality) would give them an ‘eternity to reach paradise’. If paradise were a physical place, reaching it would be primarily a matter of distance, not time (barring whatever you have to do to gain Titan’s favor and be let in). I think it’s implied that ‘paradise’ is achieving a mental state, similar to enlightenment, that the follower’s new body, stripped of un-follower-like thoughts and ideas, would facilitate.
The modifications to the followers’ bodies are primarily new ears, new lenses over the eyes, and a mask for the mouth. If you can filter out anti-Titan voices through the ears, filter out anti-Titan visions through the eyes, and filter out anti-Titan sentiment through the mouth, it’d surely be a lot easier to achieve a Titan-style enlightenment.
I still love how when Ava drank the vial she turned into this massively powerful nightmare monster, sets the TITAN HQ on fire complete with a positively stunning visual show, then hides, disses Odin for deserting her when he finds her, burns an effigy and passes the heck out.
Come to think of it, it almost sounds like Ava got some kind of superpower-ridden hard liquor and the result was a drunken rampage followed by blacking out.