Changes to DS/Unbreakable and Undying/Ruin i would make that would make them less busted
DS/Unbreakable and Undying/Ruin fit similar purposes, that being making the game less fun for the other side and given the side using them a stupidly powerful advantage, so here's some changes I would make that would let them still be strong but be infinitely less annoying
DS: After being unhooked or unhooking yourself, if the killer picks you up within 60 seconds you are able to stun them by hitting a skill check, if you are also using Unbreakable, the perk's activation time is halved but the stun will be doubled
Unbreakable: You have increased recovery time from the dying state, After unhooking another survivor, you are able to pick yourself up from the dying state once, if you are using DS, you will not be able to pick yourself up from the dying state but you will have increased recovery speed
These changes make the DS/Unbreakable combo less of a absolute "you should run this" and more of a trade-off, if you run both you give up half of DS's duration and the ability to pick yourself up from the dying state for a twice as long stun and increased recovery time (i also added the unhook another survivor to Unbreakable because I think being able to pick yourself up for free is pretty ridiculous, so adding the clause essentially makes it a Deliverance you can use whenever even if you get hooked)
Hex: Undying: If a hex totem is broken, this hex will take place that totem's effect on a random dull totem, this can only happen once per hex, this effect goes away once the hex totem is broken
By adding a hard "once per effect" clause survivors will have to only have to find bare minimum 2 hex totems, maybe 3 if they break Undying before the 2nd Ruin, but even in those situations that's still half of the worst case scenario with Undying/Ruin currently, plus I'd remove Undying's aura reveal since then it won't make TOTH completely redundant
Comments
About DS/Unbreakable:
Nah I understand what your are going for, but making specific rules for a perk combo is not good design. To give you an example compare it with exhaustion perk e.g. Exhaustion is there to limit the combinations of those in a chase. But they don't have specific rules to change each other. Instead they have a global side effect, that makes it easier to include future perks as well.
Besides that the issue isn't really with the DS/Unbreakable-Combo. It's because DS is abusable in it's current form in general, by giving survivors a basicly 60s "free pass" after an unhook. Even forcing the killer to slug is part of it beeing abusable. Unbreakable is actually fine as an anti-slug perk.
About Undying: Yeah, that would be fine probably. Making it once per Hex would balance it out a little. On the other hand, if you replace the Aura reveal, then you need something else that allows it to scale based on Tiers, because currently it's the aura reveal time. And the Hex replacing effect is not scalable. I know that sounds weird, but that's an issue DbD has to deal with in it's perk design.
The only thing left that really needs a nerfbin the killer side is IRI hatchets. Mori's, Doctor, Legion, Nurse, Freddy, insta-saw billy and old HEX ruin were the major killer issues holding things back from balance. The reason you can't nerf the ruin Undying combo is without Ruin, Undying is pretty much a useless perk.
At most of you really wanted to do this, you would have to buff Undying so that stacks don't reset on other hexes i.e. Huntress lullaby/devour hope not losing all value after the first break. And that might sound too strong, but it isn't since you only get one single replacement.. This would also greatly encourage people to start learning totem spots in each map. People won't even be as upset about this totem if they start to realise that sometimes it's best to invest the time into breaking totems first. If that buff doesn't happen, then basically the perk is only useful for ruin and it's a straight nerf, there isn't really another way to buff it outside of extending the reveal range, which could be very broken.
Your concept is a bit overly complicated for what needs to happen to DS and Unbreakable doesn't fix the main issue with the perks.
For DS, Activates for 30 seconds after a unhook, goes down 2x slower in a chase or while slugged.
For UB, Increase recovery speed, you must pick someone up from the ground if you want to pick yourself up.
For Undying, protects only 1 totem a match and is no longer a totem/hex perk, make the aura reading apply to dull totems only.