Wait, eight weeks?
Acquiring the Fangs of the Father is a pretty simple project. Raid Dragon Soul every week, complete a few assassination missions along the way, and you'll be wielding legendary daggers in just a few months. The acquisition phase has two portions: one where we open Elementium Gem Clusters to obtain Shadowy Gems, and one where we just keep the Elementium Gem Clusters.
Raiders in 10-man environments can pick up a maximum of eight clusters per week, while 25-man raiders will pick up about 15 a week. Interestingly, the drop rates don't change on heroic mode, so casual 8/8 guilds get as many clusters per week as hardcore 8/8 heroic guilds. Since both phases of the quest rely on obtaining Elementium Gem Clusters and 25-man guilds acquire clusters about twice as fast, a 25-man guild will complete about two sets of Fangs of the Father for every single set that a 10-man guild completes. It's not the 2.5:1 ratio that many people expected, but I think 2:1 is a pretty fair trade-off.
If you are clearing Dragon Soul in a 10-man raid every week, it will take you about seven weeks to obtain enough Shadowy Gems to move on to the next stage. We pick up about six gems per cluster, and we obtain eight clusters per week, which means we'll acquire 333 gems after seven weeks. For phase two, the math is even easier. Since we're guaranteed to get one cluster per boss, we know that we need to kill exactly 60 bosses to get the necessary 60 clusters. At a rate of eight bosses per week, that's about eight weeks of clearing Dragon Soul.
Add in a final Deathwing kill, and you'll have your Fangs of the Father in just under four months. For 10-man rogues, like myself or Tillman, we're only halfway there as of today, so the finish date is still two months away. If we speculate that Mists of Pandaria will be released toward the end of 2012, then there's time for three rogues to obtain the legendary daggers per 10-man raid group. Since 25-man rogues acquire their clusters about twice as fast, it only takes them eight weeks. Realistically, you could cycle through six rogues per 25-man group over the course of 2012.
Fangs of the Father vs. Dragonwrath
From start to finish, after all of the adjustments, it will take a caster in a 10-man raid about five months to acquire a Dragonwrath. While the initial time from start to finish for Dragonwrath might be longer than that of Fangs of the Father, the major difference is that multiple casters can be collecting pieces of Dragonwrath simultaneously. Only one rogue can be working on Fangs of the Father at a time, since both phases of the quest rely on Elementium Gem Clusters.
Once one rogue completes his legendary daggers, the next rogue must start from scratch. When a caster completes a Dragonwrath, there will be another caster ready to take his place on the final phase the following week. Each rogue legendary is a full 15 weeks apart, while casters will start to complete Dragonwraths every five or six weeks after the first. This allows many more casters to acquire Dragonwraths over the same period of time when compared to rogues.
The accelerated acquisition rate of Dragonwrath makes sense, since there are multiple casters per raid group but typically only a couple of rogues. The real downside to Fangs of the Father is that only the first rogues to acquire them will actually get to use them on progression content. By the time the second wave of rogues are finishing up their quest line, most guilds will have everything on farm status. It's sort of like all of the death knights and warriors who picked up Shadowmournes in Wrath's waning hours, only to replace them with blue weapons from early Cataclysm quests.
Fangs of the Father aren't PvE daggers
Unless you're one of the lucky rogues who was chosen first to receive your Fangs of the Father, all PvE content will already be irrelevant by the time you acquire them. While you might think that's an oversight by the developers, it's actually the opposite.
Fangs of the Father are the first rogue-only legendary. In fact, they're the first class-specific legendary. They weren't given to us to stab Deathwing with; they were given to us to slay the opposing faction with. Do you really want to earn your legendary daggers and then only raid Dragon Soul for the next year, week in and week out? I am going to go plunge my orange stabbers into the hearts of every single Alliance player I can find, regardless of their level or intention.
Blizzard is giving me nearly a year of godlike power, and I'm not going to let that go to waste defeating the same scripted encounter 50 times. If I have my way, the Dragon Aspects will be calling a meeting later this year to figure out how to solve the rampant string of assassinations before there's no life left on Azeroth.
Sneak in every Wednesday for our Molten Front ganking guide, a deep-dive into the world of playing a subtlety rogue -- and of course, all the basics in our guide to the latest rogue gear.