I think you've got to get your head around just how volatile some of
BTG's output is, and how scummy their paytables are.
In the case of Lil' Devil the only way to really hit in the basegame is with the wilds, but they don't land very often AND connect with something.
Then you've got stupidly volatile features that can pay bugger all time and time again, along with the chase mechanic feature that'll have hundreds of times your stake off you to trigger, and cheerfully pay back 12x.
One real cash session on this was enough for me, straight on the banned list.
There's a way to do high volatility slots right, and this isn't it. I appreciate there's only so much RTP to shuffle around, but it seems to me that there's a yawning chasm in BTG's output where the 100-500x stake wins should be.
That said, put a billion spins through it and it'll return 96.4% to you, same as any other slot that's got a 96.4% RTP.