HUGE UPDATE: PTR 2.4.2 changes!
- The monster HP and damage increase is a pretty stable increase (and values up to TX haven't changed on PTR, I checked that). I extrapolated those values and also cross-checked with Ghom T10-T13 values on PTR (for HP). I've rounded up the last few digits for HP as that's an estimate; I'm sure Blizzard will update the Game Guide when the patch is out. The damage increase is a very straightforward progression and therefore those values are pretty much correct down to the last digit, I assume.
- XP/gold changes are taken from in-game tool tips on the difficulty selection screen.
- Legendary drop rates have never been confirmed for T7+ (Wyatt once posted them for up to T6), but no one ever complained and they "feel about right". Again, the increase from T1 to T6 followed a steady formula, so I just extrapolated up to T13.
- Death's Breaths: I did some runs and also watched some videos, and also checked lower difficulties (99% sure those are unchanged). T13 seems to have guaranteed 2 DB drops and a chance for 3rd, from my testing 25% looked about right and also makes sense in terms of the other values. But it could also be anything between 15% and 50%. More data welcome.
- Bounty cache mats is confirmed by multiple posts on the PTR forums.
- GR keys is hard to tell, as the patch notes are relatively vague and it needs a TON of data to test this for every difficulty. If you look at the wording the scaling I assumed makes most sense (10% increase per difficulty). But this is where we need most data!
- Keywarden machine drop - again, interpreting the patch notes this was the only progression that made sense in my opinion. But if anyone wants to go through the effort to do a large sample of keywardens to confirm/update this data, you're welcome.
- I have no idea about the horadric cache legendaries. Honestly, I myself don't have the time to run dozen of bounties on T11-T13...
- Ubers (update): Did a few T13 runs and got 3 organs every time. This has to be a joke... Realm of Fright on T13 ain't no joke (it feels like fighting 3 GR80 rift guardians), it should reward at least 5 mats.
TL;DR: Most data is extrapolated or "patch note interpretation" and probably pretty accurate. Need data on GR keys, machine/organ drops, cache legendaries.
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