Hydreigon is good in OU, especially the Specs set, LO is also good but you are messing the tiers up and your set is pretty flawed, it should be specially based and yours doesn't even have Dark Pulse, the reason to use Hydreigon. Superpower and Iron Tail are both UU things, if you want the sets for a pokemon, be sure you check the correct tier, Superpower is used in UU to beat Blissey and Snorlax, who aren't relevant in OU and here Flash Cannon is better than Iron Tail, you mentioned both Sylveon and Florges but those aren't viable here either, Flash Cannon is enough to 2hko Clefable so that's what we use.
Basically, this is the OU forum and you should stick only to OU stuff, you mentioned monotype and that's irrelevant here and the UU matches/matches against newbies who use unviable pokemon from UU aren't important too, i'd say you have to learn more about the tier first, check the viability rankings and focus on mastering standard sets instead of trying to make those sets when there are already similar ones that are better, not to discourage you or anything but when you don't have much experience yet you should do that, using basic sets and preparing for them because they are the most effective and your opponent is likely to have those too.
Of course, if you manage to come up with a creative set or if you find a niche for a rare pokemon, you can talk about it here but remember that you have to take in consideration that you should only do that if you are convinced that your set is consistent, not outclassed, not gimmicky and works well against more skilled players but that requires a bit more of experience since you have to know the metagame very well first, keep playing and use this forum to try to learn more about the metagame by checking useful links, hearing what more experienced players say and trying to discuss here while asking for advice.
By the way, Scope Lens is useless on Hydreigon because almost all the time you have no item pretty much, it just gives you a little bit of luck, Earth Power isn't very good because Dark Pulse deals alot of damage to Heatran already, especially since most of them don't invest in spD and the problem with Superpower is that it almost only hits Chansey who only appears on stall pretty much and it doesn't even 2HKO her due to the atk drops so the opponent can Softboiled there, if you want Hydreigon to beat stall then use Choice Specs Hydreigon + Screech Dugtrio as Dugtrio traps Chansey and Screech removes its def so it can't cure itself with Soft-Boiled and when Chansey is gone, Hydreigon can freely spam its special moves and defeat the rest of the team.