This team needs a few improvments...
To start off with when im suggesting improvements i will add natures which you have seemed to of missed.
Hydreigon is ment to be a special sweeper but can be used as a physichal but not a mixed.
Its spatk is far better than any of the other peswado legendarys so ill use a special set.
Item- dont use black glasses, is that small boost on one move worth it?
instead go an item such as life orb which adds 30% to all offensive moves, but does have the cost of about 1/12th hp loss in return.
Nature- go timid(-atk +speed) or modest(-atk +spatk)
Evs- 252spatk 252speed
Moves- well replace crunch with dark pulse.
and defintly dont go strength instead go uturn for scouting and replace dragon pulse for draco meteor.
U turn may get the atk loss but can deal good damage still as well as get rid of draco meteors spatk loss.
Lucario may have better spatk but only by 5base points thats like a differance of 10 at lv 100 with max atk and spatk.
Lucario also has more options when using a pysichal set due to its great movepool.
Item- wise glassess, once again a terrible item compared to the life orb which i would highly recomend on lucario.
Nature- once again modest or timid but timid would probobly be your best option in ou.
Evs- everything is fine here.
Moves- thats an ok movest but if your running a special set go nasty plot that will make you deal tons of damage as well as maybe replace dragon pulse for hidden power ice that takes care of dragons and ground types.
I think you have an illeagle movest there.
In most tiers and competative batteling flash and minimize is band.
also what the heck is it holding the evolite for :p
Item- Evolite: An item that boosts nfe pokemons def and spdef by 50%
Blissey is fully evolved so does not get the boost so i would go for the best item for blissey, leftovers of course.
Nature- errrr im not to sure im looking all over the web and there telling me to go bold but bold at lv 100 only adds on 11def points the equilivent of 44evs maybe a spdef nature.
Evs- looks great as it is.
Moves- as i said you have to illeagle moves 1 of which is not a good choice.
Why have minimize and flash, if you are going to keep one keep minimize that will give you a constant evasiense boost which in effect lowers the foes accuracy where as flash lowers one pokemons accuracy.
toxic is a must and so is softboiled.
I like to run protect on blissey give you a free turn of healing and the foe a free turn of poisening :)
seiscmic toss is also a must (does damage equivilent to the foes level) there for the foe is loosing an increasing poisening amount as well as 100 damage every turn from seismic toss.
Your evs are messed up and wasting 4 also golurk is a pysichal pokemon and shadow ball will not peform as well as another ghost move thats pysichal.
Golurk is already a slow pokemon so we can use this to his advantage.
Item- kings rock has a 10% chance of making the opponent flinch so you could go 9 moves and it may not work you could go 20 moves and it still may not work but thats just bad look.
leftovers is probably your best option.
Nature- brave(+atk -speed)
Evs Just go 252atk 252spdef or hp its easyer and more effective than what you have got , also 63 evs your wasting 2 evs there 63/4 does not go.
Moves- as i said we can use its speed to an advantage.
This set gos pretty well with the ability iron fist(boosting punching moves by 20%)
so go hammer arm(good power and gets iron fist boost also lowers speed)
shadow punch instead of shadow ball that way you get the iron fist boost and stab making its power 108.
Earthquake is the best stab and probably the most overused move in the game.
Finally the speed advantage gyro ball.
Another pswedo legendery which lost alot of its fans in gen 5 but yet is still a great pokemon witha good movepool and offenses which you are killing with normal gem and hyper beem, dont get me wrong hyper beem and normal gem will do alot of damage but is it worth it.
Its speed isnt the best but will outspeed most ground, rock and steel types, its speed is still worth raising though.
Item- dont use normal gem but if you decide to use it for some bizzare reason go giga impact at leest seen as its atk is far better than its spatk.
instead go an item like leftovers or even expert belt.
Nature- adamant(+atk -spatk) or jolly(-spatk +speed)
Evs- 252atk and 252speed or 252atk and 252def or 252atk and 252hp or 252atk, 126hpand 126speed.
Moves- If you do go normal gem again for a very bizzare reason explosion is there ready to do 500 base power but i would go bullet punch with 60 base power when stab is added it is a good move because it has +1 priority making it almost always go first(like quik attack)
bullet punch is a good move to kill them enemys that have just kod your last pokemon and on low hp.
meteor mash is also a great option as well as zen headbutt, earthquake and agility for speed boosting.
For your last pokemon im not to sure who to pick my minds blank but if this is for po espeon is a good option with magic bounce as it lets you bounce back entery hazards or you could go with a pokemon that can set up entery hazards or even support your team with moves that boosts your teams speed for 5 turns (cant remember the name)
maybe even a baton passer such as ninjask with protect swords dance substitute and baton pass.
that alows you to get at least a increased 4stages in atk and speed then baton pass to some one like metagross which becomes insanely powerfull and quik.
hope this helped
it turns out you added in deoxys while i was answering so ill make a few quik points.
first off though speed form looks cool is it worth that extra speed which isnt really needed and the extra def boost which comes at cost of a major offense loss making its stats excluding speed a bit above average.
an atk form may be better or better yet a def form with spikes to make a good lead.
the evs are messed up as you are missing 2 as well as your moves dont exist.
i will go a lead deoxys
so this one i admit is off smogon but is a good set with its now decent def another set i saw used the dual screens making a good support pokemon.