Blissey can actually withstand physical attacks and is only KOed after 2-3 strong attacks, unless they are STAB Fighting which usually OHKO or 2HKO her. She can take strong attacks and counter back. She can actually take Physical hits better than Skarmory can take Special hits. I won't even bother talking about her special defensive capabilities. Waste of time. She.Doesn't.Die. EVER!
Anyway, I have done so many calcs and Blissey doesn't get OHKOed by anything apart from boosted attacks or STAB 75BP(and higher) Fighting attacks from a Base Att of 120 and higher. This will be an instant OHKO. Anything lower and she will need 2 hits. Anything else than Fighting attacks need 2-3 as well. And these are with a LO. In the wild no items would exist. They are artificial.
Okay now let's analyze these situations. In the wild, Pokemon usually attack straight forward instead of dancing random dances to raise their stats. The attacks mentioned are attacks that these Pokemon are expected to use
1. Clefable is hardy and has strong defenses and good HP so she would be hard to take down.Also, she is larger and heavier than Weavile. In the wild, Weavile, like wild animals, would attack with his claws. So Slash does max 21% . Crunch 35% and Ice Punch the same(almost). So I can't see him winning it. Clefable would just take the hits easily and recover(Softboiled) and steadily attack back with her claws and fangs. A Clefable's Slash does about 35% to Weavile. So he would go down easily. Double Edge from Clefable would destroy him in 2 hits.
2. Wigglytuff is once again quite tough. She has a ton of stamina so Luxray would tire out much faster. Wigglytuff would just use Sing and escape. If not, she could Double Edge and Body Slam with her inflated body while stopping him in his tracks with Disable. She can take hits assaults easily as Crunch does only 25%, Slash does 22%, Double-Edge does 37%, Wild Charge around 45%. So, she could win that. She can recover damage with Wish as well. It may seem odd, a bunny beating a lion but Wigglytuff is bulky and large. It's still 50-50 as Wigglytuff is kinda smaller. Thunderbolts are also well endured. So Wigglytuff has its bulkiness, stamina and inflated Body Slams while Luxray has speed, offense and even thunder wave to paralyze.
3. Blissey has ginormous stamina and reliable healing,Softboiled. She can take and heal. Meanwhile, she can paralyze with T-wave and Seismic Toss, all while regaining health back. Arcanine sure is strong. The only concern is that he can use Close Combat. Okay in this rare case(how often do you see lions exchanging punches and kicks?) Blissey will succumb. Otherwise, on a more logical plan, Arcanine, being a canine thing, would bite, slash and tackle. Double Edge does 38%. Crunch does 25%. Slash does 22% and his most powerful, Flare Blitz, does 57%. Blissey can certainly take all of his assaults with ease, except the latter, and retaliate back with Twave and continue with healing and slowly taking him down. Flare Blitz? After the first hit, use Counter or even T-wave again and then heal. Blissey, won't have fun but she can certainly survive and even win. Her explosive eggs will also give trouble to that lion. Chances are, her humongous stamina will get her going while Arcanine will be drained of life much sooner.
4. To cut long story short, read the above. Only difference, Tauros will attack with horn attack,double edge, megahorn or giga impact. Horn Attack 29%, Giga Impact 66% , Double Edge 53%, Megahorn 35%. Blissey takes them, paralyzes, heals and seismic tosses.
5. Okay. What can Vaporeon do? Oh yeah. Special attacks would kill Blissey by too much laughing. Physical attacks? Yeah, only STAB Aqua Tail which does 30% even Giga Impact does 34%. Okay, the thing here is that both are very bulky and defensive. In the previous scenarios, it was attack vs defense. Now it's defense vs defense. Vaporeon is bulky as well yet its attacks can't hurt Blissey, even Aqua Tail. Blissey takes it easily and can also evade it due to low accuracy. So, as both of them can't physically hurt each other they may Toxic each other. And as Blissey has more HP she will outlast Vaporeon with Softboiled and even Heal Bell.
6. The same as above. Clefable can't get poisoned though but nor can it hurt Blissey as its attacks will only 4HKO and 5HKO it. Anyway, it will be a long, really really long battle but Blissey may have the upper hand as she is bulkier and can kill Clefable with 4 ST while Clefable kills Blissey after 7 or 8(if HP is fully max at 714).
