Hello and Welcome, my name is Lilium and i present to you this guide to earn what is now the rarest achievement in the game, we gonna talk about « But I Trusted You » a secret achievement who as i speak was only claim by 0,2 % of the player of Corruption of Champion 2, i will take for myself than you peoples know most of the location and story element so i will not explain outside of what needed for this specific achievment, let’s get into it

it’s recommended than you restart a new save for what folow, we gonna start with the prologue, because yes this time it’s not recomended than you skip it…
the goal is to be on the good side of Kassyra, and the only way to do it is having sex or having friendly converstion with with her as much as you can before the winter city event, here the event who let you do it (do her) :

1- In the prologue after she get summon
2- Right after Meeting Ryn, after the fight with the alraune
3-After beating the alraune she can appear in your bed at night, be friendly
Bonus- the Halloween event also count as a point

From all ot the top « spot » you can be friendly to her, only doing two of them is enough to be consider on the romance path with Kassyra

you also need to do the kyoko sidequest, retrieving the amulet and freeing her, knock her and have Kinu, enter the Fox den and free her

...and at the same aswell time continue Cait story line to get the Mallach temple in Hawkthorne

I’m not gonna talk long about that part to avoid most of the spoil, do like a casual run and enter the castle, beat the Elves and Queen Alyssa, but when Kassyra appear, be friendly, Hug her for example, and at this point it will change the storyline of the end of the Event, it’s pretty funny and interesting on my point of view,

That say after that Event you will become officialy in « Romance » with Kassyra, she will give you access to her little castle in the way between (located above the foothill waystone)

After Being on the Good side of Kassyra, you need to return at the Frost Hound and sleep, when you wake up you will open the map and check the temple of Mallach than you have build earlier by finishing Cait Questline

What you want is to spot a random event who will occur in the temple (star icon on the map), the event is random and can spawn everytime you sleep, so you need to spam the bed till it appear

finally when the event is there, you need to go for it, you will meet a really strange catfolk who are in fact Kassyra in disguise, after revealling her the ruckus gonna oblige Mallach to appear

After a bit of Dialogue Mallach will ask you what do you think Kassyra will do with your soul, You need to respond « She want a child » and after that finish the event as usual

After all this Event you will return to the kitsune den, before meeting Keros you need to do at least one of the quest from Nakano, i choose the artificier quest in my save,
and when Keros appear, sell your soul to him and become a fluffy kitsune

Now it’s time to tell your Demonic girlfriend about it, Go to her dream palace in the way between, speak to her (do note than she’s not in her palace most the time, you can spam the bed to found a day where she’s here)

And choose to talk about your soul, and tell her than you are soulbound to Keros, congrats, you break the heart of a Demon

And she cannot trust you anymore