I'll admit I was originally opposed to
Doom Desire/Future Sight mainly because of the delay and the opportunities it gave the opponent, but I recently tried a Heatran set in Balanced Hackmons that looked like this, and now find myself strongly supporting them:
Heatran @
Lum Berry
Trait: Levitate
Timid Nature
EVs: 252 HP / 252 Atk / 252 Def / 252 SpA / 252 SpD / 252 Spe
- Doom Desire
- Fire Blast
- Volt Switch
- Protect
And never once has Doom Desire failed to do me any good. It forces all kinds of interesting positions. Granted, BH is a VERY different metagame than OU, but this example does show that under the right conditions Doom Desire can be a hell of a move. With that said, let's consider the questions we've asked with this concept.
[*]What mechanics of Pokémon determine how viable moves are?--not only the Pokémon's typing, stats, and ability, but also its interaction with playstyles and momentum.
[*]What new strategies might emerge by giving a new OU Pokémon underused moves?
[*]What challenges do Pokémon that use lesser-used moves face compared to ones that use a more standard moveset?
[*]If the Pokémon has options of staple OU moves (high-powered STABs, offensive stat-boosting moves, reliable recovery, Substitute), will those moves be useful to it, even if it's specialized toward a separate and distinct strategy?
[*]Can underused moves increase other underused moves' viabilities?
[*]Can one user of a strategy unrecognized in a metagame massively influence a pre-existing playstyle?
The first point here relates to move mechanics, and Doom Desire/Future Sight (henceforth DD/FS) have a mechanic unique to them that no one uses in standard environments due tot here being nothing viable to do it with. Using DD/FS as a focus of CAP6 introduces this new mechanic to OU in a way it actually works (yes jas, I know you have a Rachi set that runs Doom Desire, you beat me handily with that team the one time I faced it). Jas's Rachi set aside though, this is unexplored territory. The only real way we have to look at the viability of these moves at the moment is the Hackmons and STABmons tiers.
The second relates to new strategies. As far as DD/FS go, this is directly linked to the first one. Introducing a viable new mechanic opens up all kinds of new strategies. We saw this when Gen 5 first started. Suddenly permanent weather was available in OU. Trick Room became more viable with the advent of Pokemon like Reuniclus and Conkeldurr. Magic Bounce added a whole new level to entry hazards. The list goes on.
The third point, I think, depends on the movepool we give this CAP. The use of a move like DD/FS would require a set (or team) built to take advantage of the pressure it puts on the opponent. Unexplored territory always brings challenges with it, and it seems to me that whatever move(s) we pick the challenges of basing something around that move or those moves will become more apparent as we get farther along in the project.
The fourth point, I think, depends on us. Going back to my Heatran example, we know Heatran can use its standard moves effectively in the OU tier. It can also use more standard moves effectively in the BH tier. My use of DD on Heatran in the BH tier has been very successful for me thus far. This would indicate that it is possible to have an either/or situation, or a situation in which both a lesser-used move and a more standard move (DD and Fire Blast here) combine to make the set effective. (I believe the Heatran scenario was explored by someone else in this thread too, but I can't find the comment to quote here)
As for the fifth point, all I have to say is yes. We already know from the previous discussion on these moves what DD/FS do mindgames-wise and pressure-wise. Several underused moves can be used to encourage other underused moves that would work in tandem with DD/FS to allow the user to choose whether they want to hit the Pokemon currently in or let the opponent switch. The moves I'm looking at here are trapping moves like Wrap and Whirlpool (and Magma Storm, but the signature moves of 2 different Legendaries is pushing it, I think). Suppose you wanted to hit the Pokemon that was already in with DD/FS. These moves allow for that. I'm not saying the use of DD/FS single-handedly makes Wrap and Whirlpool viable, but it does make them usable. Personally, I'd prefer something more like the Heatran set or Roar, but barring those as options Wrap or Whirlpool may made interesting choices as trapping moves. Additionally, Mean Look and Spider Web trap without the damage but more reliably. Not trying to poll-jump here but along with DD/FS I think Shadow Tag would actually hinder more than it would help since you don't always want them trapped. Often DD/FS and letting them switch is better. It's definitely good for momentum alongside Volt Switch or U-Turn, but having the option to either trap or let switch would open a few new avenues of exploration for DD/FS.
As for the sixth and final point the strategy I see these moves most influencing is VoltTurn, since it's all about pressuring the opponent and keeping momentum. This is something I may explore more in OU with DD/U-Turn Rachi. The idea here is that an effective DD/FS user would force switches to a Steel/Psychic resist/immunity. Everything and its mother gets Protect, it seems, so for the sake of argument I'll say this CAP does too (again, sorry for poll-jumping here, these last 2 points seem to a lot more than I intended). DD/FS, Protect to scout and then U-Turn, or eliminate the Protect step and just U-Turn (U-Turn and Volt Switch are interchangeable here). I haven't tried this yet, so momentum-wise I'm not sure if it's actually as effective as it seems but it seems like it would be wonderful for that, which helps out the VoltTurn strategy tremendously. So my answer to Question 6 as far as DD/FS goes is also yes.
tl;dr: I liek Doom Desire/Future Sight