The choice of a screener really depends on your team's needs.
-Deoxys-S guarantees screens and is still good at preventing hazards, isn't set-up fodder, protects the switch-in from status and can set up his own hazards. Ice Beam is also a good option, 2HKOing every Prankster.
-Espeon completely stops hazards and doesn't fear taunt, but is set-up fodder and not nearly as reliable. Fails hard against Choiced TTars and Volcarona.
-Latias is reliable, can screen twice and has healing wish, but does nothing against hazards and is set-up fodder without Roar.
-Latios is still reliable, is never set up fodder, has kill power and can allow anything to set up with Memento.
As for Virizion... I think he's pretty much outclassed by the others. He can't guarantee screens because of its weaknesses and moderate speed, but doesn't have anything else to offer. HO isn't exactly the most subtle playstyle with team preview, so I wouldn't risk going up against Starmie/Darmanitan/Volcarona/Gliscor/Tornadus/etc.
As for Kingdra, I was talking about this set specifically :
name: Mixed Rain Dance
move 1: Rain Dance
move 2: Waterfall
move 3: Hydro Pump
move 4: Draco Meteor
ability: Swift Swim
nature: Mild
item: Life Orb
evs: 92 Atk / 252 SpA / 164 Spe
Volcarona won't cause you any trouble when you completely wall Ninetales and set up Rain Dance on him. Lum Berry could help against the occasional Hypnosis (Waterfall is mostly for Blissey and cleaning), but you absolutely need LO's sweeping power. With it, Kingdra OHKOes everything under rain bar water-resisting special walls and SpD Jirachi (2HKO). Even defensive Rotom-W can't take a DM after rocks.
-Deoxys-S guarantees screens and is still good at preventing hazards, isn't set-up fodder, protects the switch-in from status and can set up his own hazards. Ice Beam is also a good option, 2HKOing every Prankster.
-Espeon completely stops hazards and doesn't fear taunt, but is set-up fodder and not nearly as reliable. Fails hard against Choiced TTars and Volcarona.
-Latias is reliable, can screen twice and has healing wish, but does nothing against hazards and is set-up fodder without Roar.
-Latios is still reliable, is never set up fodder, has kill power and can allow anything to set up with Memento.
As for Virizion... I think he's pretty much outclassed by the others. He can't guarantee screens because of its weaknesses and moderate speed, but doesn't have anything else to offer. HO isn't exactly the most subtle playstyle with team preview, so I wouldn't risk going up against Starmie/Darmanitan/Volcarona/Gliscor/Tornadus/etc.
And on Kingdra, I agree with alphatron on this one, Chesto rest just isn't as good as it used to be since the Drizzle nerf, and definitely not against Sun with Volcarona's on just about every Sun team. Kingdra does well against mostly everything on Sun teams but Volcarona unless you lock yourself into Outrage, I'm guessing Lum berry?
As for Kingdra, I was talking about this set specifically :
name: Mixed Rain Dance
move 1: Rain Dance
move 2: Waterfall
move 3: Hydro Pump
move 4: Draco Meteor
ability: Swift Swim
nature: Mild
item: Life Orb
evs: 92 Atk / 252 SpA / 164 Spe
Volcarona won't cause you any trouble when you completely wall Ninetales and set up Rain Dance on him. Lum Berry could help against the occasional Hypnosis (Waterfall is mostly for Blissey and cleaning), but you absolutely need LO's sweeping power. With it, Kingdra OHKOes everything under rain bar water-resisting special walls and SpD Jirachi (2HKO). Even defensive Rotom-W can't take a DM after rocks.











