If you're really desperate it can do a job as a stallbreaker. Problem is we have so many other stallbreakers who aren't deadweight vs other styles.
Let's talk about Ditto!
I think that Ditto should be promoted from bottom of C-. It's one of the most misunderstood pokemon in high lvl meta. It's not necessarily just a gimmicky ct vs ho.
Misconception that Ditto is bad vs Stall:
IDK why ppl say this. In reality, Ditto is one of the best stallbreaker in game. Ditto can easily come into whatever and infinitely rest/heal up your team with no PP drain. It'll take very long but you will win 99% games vs stall as Ditto if you patiently PP stalls everything.
The biggest issue for Ditto is balance. However, there has been a notable trend of using powerful wallbreakers in balance teams. So, you can easily exploit that and reverse-wall break. This isn't always true tho, and there's some absolutely awful match up for Ditto. But, I think that the current ORAS meta is the best meta possible for Ditto to succeed in.
It acts as a nice check to Primal Groudon's without Dragon Claw and can remove hazards as well. Although the Latis can also do this, but its typing helps it against certain threats more easily.
On an unrelated note, I'm curious as to why Flygon is C+. I'm not asking for it to drop or anything, I'm just wondering.
Yeah okay, I forgot to take this strongly into consideration when making my post and the superiority of Tina-O, you've convinced me the Cons out weigh the negatives of my nomination, Im a bit bias towards them aswell since they are commonly present on my builds. Im gonna retract my support on Lugia/dragonceus, though I would still like to keep my Arc-fairy nomination in place.I'm gonna step in and say Arceus-Dragon and Lugia are completely fine at their current rankings.
Dragonceus's weaknesses are significant enough to keep it from moving up. Yes, it offers some cool role compression since it can check Mence, Ho-Oh, and PDon while still having room for Defog, but it's bait for some very common mons (fairies, steels). Diancie forces Dragonceus teams to run a niche steel capable of checking it, since bulky offense usually relies on their Arc-forme (sd ground / waterceus) to do so. Klefki forces a team composition that either isn't weak to hazards, has multiple mons that force Keys out, or has a Magic Bouncer in order to keep it from being a huge pain in the ass. Giving Xern free turns is obviously bad, not much to say there. It's weaknesses are also much more relevant than Waterceus's, since Dragon and Fairy are very common attacking types (especially since it's weak to PDon's D-Tail).
Lugia has similar flaws to Dragonceus, namely being bait for some particularly threatening mons (Darkrai, WoW Gar, every steel type ever aka spikes setters). It also fails to check much of anything if SR is up, meaning it needs a strong hazard removal core backing it. Due to the support it needs, Lugia only fits well on a few niche team compositions and is generally outclassed by Tina-O on most bulky offense and balance, since Tina-O actually checks SD grounds well and doesn't cede momentum.