Is there something like a soft pity?

Ok so hear me out, I'm a veteran gacha player and since the sanctum is a gacha i was wondering if there were a kind of soft pity like you have higher chance to get it between 65 to 70 instead of whole 80 pulls. If that's so the skin could cost mire like 200 than 250 which still a robery lmao but can make a difference. Still hesitating about taking the skin as fellow jinx mid enjoyer (yes i know it's not optimal but it works perfectly fine even in emerald elo) but it'll depend on too many factors lmao. Also do we know how long it last since the sanctum is the only way now to get mythic essence if it last for 42 days for example that means after that we just can't get mythic essence anymore till next sanctum, seems weird to me.