Ubers my favorite :D
Groudon
If you want a sweeping set then use this set.
Groudon @Life orb
Trait: Drought
EVs: 80 HP / 252 Atk / 174 Spe
Adamant Nature
-Earthquake
-Stone Edge
-Rock Polish
-Swords Dance
This set is very underrated and probably the deadliest set in the whole Metagame as set up is easy thanks to his amazing bulk.
Once a Rock Polish is up you can sweep away, though Swords Dance is a very decent option after if you can take the hit.
Dont be put off by the double dance set, it works brilliantly and helped me 5-0 Fate.
Groudon @Leftovers
Trait: Drought
EVs: 252 HP / 4 Atk / 252 Def
Impish Nature
-Thunder Wave
-Dragon Tail
-Earthquake
-Stone Edge
A stalling set that provides great support for the team in paralysis and phasing.
Ho-oH
Perfect though Regenerater is needed.
Forretress
Okay so hes got terrible SDef even with investment and even with it your not suviving any special fire attacks or a Water Spout from Kyogre.
Try this following set.
Forretress @Leftovers
Trait: Sturdy
EVs: 252 HP / 252 Def / 4 SDef
Bold Nature
-Rapid Spin
-Spikes
-Stealth Rock
-Volt Switch
This allows you to sponge the dragon hits easier you already have Pokemon to take its special hits.
Rapid Spin is needed over T-Spikes for Ho-oH.
Lugia
I love this Pokemon so bad but I never use it.
Either way your set is OK but try this.
Lugia @Leftovers
Trait: Pressure
EVs: 252 HP / 176 Def / 80 Spe
Bold Nature
-Whirlwind
-Substitute
-Toxic
-Roost
Now this set is very fun to use, Whirlwind is over Dragon Tail as it prevents subs but Dragon Tail is an Option.
Sub and Roost are stalling while they are phased away and die of poison.
Whirlwind goes great with Forretress, Toxic is to add to the stalling.
Darkrai
Perfect though Life Orb may be useful.
Giratina
Perfect also.