NA 329.130 
• EU 406.118
While some of this is likely still inaccurate due to missing drop %s, there are a couple of main takeaways that will be useful to know for players.
In Wowheads official post they quote:
Two nights ago, at ~9:40 PST. Blizzard announced that Bad Luck Protection on the 2H Axe Legendary, 
Fyr’alath the Dreamrender was buffed. As mentioned here, we believe that most of the hotfixes to the Curves were for the Greater and Lesser Embers of Fyr’alath. However, there were also hotfixes for 2 more Curves. These Curves were actually added in Patch 10.1.5, but look oddly similarly to what we think are the Fyr’alath Curves.
Since the increased amount of Drop Chance, that we also reported here, Wowhead took it on themself and compared the newly imported, but encrypted strings and came up with the following conclusion.
Beware that Blizzard has never announced an official Drop Rate for these Legendary Weapon, and this all has been datamined by Wowhead.
If these plots are related to the legendary and they work how we think they work, these are some of the most important conclusions:
Nasz’uro, the Unbound Legacy guaranteed. Nasz’uro, the Unbound Legacy guaranteed.There were 18 weeks between the release of Patch 10.1.5 (when BLP started) and Amidrassil released. If you killed Heroic Sark every week since BLP launched and haven’t touched it since Amirdrassil, you would start on Row 18 for Heroic — now 47.5% (was 28%).
| # of Previous Sarkareth Kills | Heroic | Mythic | ||
| New | Old | New | Old | |
| 0 | 0% | 0% | 0% | 0% |
| 1 | ~1.29% | 1% | 5.4% | 3% |
| 2 | ~2.57% | 2% | 10.8% | 6% |
| 3 | ~3.86% | 3% | 16.2% | 9% |
| 4 | ~5.14% | 4% | 21.6% | 12% |
| 5 | ~6.43% | 5% | 27% | 15% |
| 6 | ~7.71% | 6% | 100% | 18% |
| 7 | 9% | 7% | 21% | |
| 8 | 20% | 8% | 24% | |
| 9 | 22.5% | 9% | 27% | |
| 10 | 25% | 20% | 100% | |
| 11 | 28.25% | 21% | ||
| 12 | 31% | 22% | ||
| 13 | 33.75% | 23% | ||
| 14 | 36.5% | 24% | ||
| 15 | 39.25% | 25% | ||
| 16 | 42% | 26% | ||
| 17 | 44.75% | 27% | ||
| 18 | 47.5% | 28% | ||
| 19 | 50.25% | 29% | ||
| 20 | 53% | 30% | ||
| 40 | 100% | 50% | ||
If these plots are related to the legendary and they work how we think they work, these are some of the most important conclusions:
Fyr’alath the Dreamrender. Fyr’alath the Dreamrender.We are currently on Week 15 since Amirdrassil came out. RWF ended on Week 2 and the legendary unlocked on Week 3. This means that this week is a Fyrakk kill with up to 12 BLP stacks.
| # of Greater Embers (Fyrakk Kills Since Week 3) | LFR | Normal | Heroic | Mythic | ||||
| New | Old | New | Old | New | Old | New | Old | |
| 0 | 0% | 0% | 0% | 0% | 0% | 0% | 5% | 5% |
| 1 | 0% | 0% | 0% | 0% | 1.5% | 1.5% | 6.6% | ~5.89% |
| 2 | 0% | 0% | ~0.29% | ~0.18% | 2.25% | 1.95% | 8.2% | ~6.78% |
| 3 | ~0.17% | 0.1% | ~0.57% | ~0.36% | 3% | 2.4% | 9.8% | ~7.67% |
| 4 | ~0.33% | 0.2% | ~0.86% | ~0.55% | 3.75% | 2.85% | 11.4% | ~8.56% |
| 5 | ~0.5% | 0.3% | ~1.14% | ~0.73% | 4.5% | 3.3% | 13% | ~9.44% |
| 6 | ~0.67% | 0.4% | ~1.43% | ~0.91% | 5.25% | 3.75% | 100% | ~10.33% |
| 7 | ~0.83% | 0.5% | ~1.71% | ~1.09% | 6% | 4.2% | ~11.22% | |
| 8 | 1% | 0.6% | 2% | ~1.27% | 15% | 4.65% | ~12.11% | |
| 9 | ~1.44% | 0.7% | ~2.88% | ~1.45% | 18% | 5.1% | 13% | |
| 10 | ~1.88% | 0.8% | 3.75% | ~1.64% | 21% | 5.55% | 100% | |
| 11 | ~2.31% | 0.9% | ~4.62% | ~1.82% | 24% | 6% | ||
| 12 | 2.75% | 1% | 5.5% | 2% | 27% | 15% | ||
| 13 | ~3.18% | ~1.32% | ~6.38% | ~2.64% | 30% | ~15.54% | ||
| 14 | ~3.62% | ~1.64% | 7.25% | ~3.29% | 100% | ~16.07% | ||
| 15 | ~4.06% | ~1.96% | ~8.12% | ~3.93% | ~16.61% | |||
| 16 | 4.5% | ~2.29% | 9% | ~4.57% | ~17.14% | |||
| 40 | 15% | 10% | 30% | 20% | 30% | |||
