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Hoo boy. THAT Skeleton vs Shadow Ghost.
I was gonna bring up what Lepyr said about Mean Look. But yeah. Mega Gengar? Okay. Well, so much for the possibility of Gengar being immune to Sans's bones because Levitate & precedent of Bone-attacks in Pokemon being Ground-type....
ANYWAY.... In my understanding, Sans is a very lazy, often joking & often somewhat dispassionate opponent; He fought Chara so fiercely because Chara had killed most everyone in the underground & he wanted to keep Chara from advancing -making the anomaly/player give up- for as long as possible.
I doubt Mega Gengar killed everyone Sans loves.
So it's questionable if Sans is at his most motivated to win this. Gengar often isn't very serious either, as its Pokedex entries & our page note its love of mischeif, which may lead to it fooling around too much....
HOWEVER. I doubt this Gengar was BORN a Gengar. Gastly is known to Poison & suffocate prey, Haunter's touch & life-draining lick cause shuddering until the victim's demise, & Gengar itself....
Moo | It apparently wishes for a traveling companion. Since it was once human itself, it tries to create one by taking the lives of other humans. |
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Gengar is probably taking A LOT of damage from soul attacks, & Karmic Retribution means each attack will be adding extra damage.
Does Sans need to be able to know where Gengar is to attack it? Can Soul attacks be dodged? I'd like to think so, but both are big factors here; Gengar probably will last a while, even with extra damage, thanks to its City Level durability vs Sans's Wall or Unknown level offenses.
Not to mention, as per Sans's own profile here:
"
Sans is incredibly lazy, and will not fight or use the full extent of his abilities unless absolutely necessary"
So what can Gengar do that can seal the deal?
Well, obviously, there's Mean Look. I doubt lazy, unenthusiastic Sans will think to dodge what appears to be just an unpleasant gaze, before the fight starts, or midway through; What would cue him in that it's more than a nasty stare, & it has some effects, as opposed to just being a chance to rest?
If Mean Look does hit, Sans likely can't Teleport.
There's also the possibility of Mega Gengar's Shadow Tag reducing Sans's mobility.
Failing that, Gengar has:
1. Disable: If Disable hits, it could interfere with Sans using his hax -like teleportation, gravity manipulation, or his soul attacks- and such.
2.
Confuse Ray .
Stad | A sinister flash of light makes the target confused. A special Ghost-type technique. |
If we count Confuse Ray as light speed, it might cause Sans issues; He scales to someone who dodged sunlight apparently, but he's still Unknown, & it is Speed Equalized against someone with a known rating of At Least Transonic. If it did hit, Sans failing to dodge or hitting himself in confusion could doom him.
3.
Hypnosis .
Yes, Sans HAS dodged while asleep after falling asleep during inactivity while fatigued... but he was also serious, fighting his mortal enemy to keep them from advancing for as long as possible. I'd think he'd be less alert here than against Chara, who killed most everyone he cares about & wanted to keep in combat as long as possible.
Also, he might be less ABLE &/or WILLING to dodge when put into a "deep sleep" via hypnotic suggestion.
If Hypnosis works anyway.
4.
Shadow Sneak .
BWB2W2
XYORAS SM
| The user extends its shadow and attacks the target from behind. This move always goes first. |
Between Gengar's other attacks -Ex: Shadow Ball, Dark Pulse, Sucker Punch, Shadow Punch- etc. Sans having to pay attention to the surfaces of the arena in the event that Gengar's extended shadow kills him while he's dealing with other attacks would tax Sans's endurance & focus here.
5. Spite: Spite can severely deplete Sans's stamina after Sans's attacks, which is just another way Gengar can challenge it.
Lastly, Gengar is known to hide in Shadows, which may be able to confuse Sans.
To summarize:
Sans is either Wall level or Unknown via Soul Hax according to his profile. He'll be dealing double damage via Gengar's typing -unless Bones=Ground & Gengar has Levitate- & more thanks to Karmic Retribution, as all of Gengar's line is known or strongly implied to kill.
Against roughly City Level durability with some level of durability ignoring attacks, Sans might be able to kill Gengar....
But Sans is likely to be dispassionate, lazy, & unmotivated during this fight, being that it's unlikely he knows Gengar & not necessarily cares about its victims or sins.
Between that & not knowing of Gengar's hax like rays of confusion-inducing light, psychically hypnotizing him into deep sleep, Shadow Tag & Mean Look impeding his mobility, & Shadow Sneak possibly killing Sans while his attention is unfocused & on other attacks....
There are A LOT of things that can go wrong for Sans here.
Both fighters have a risk of goofing around too much in the fight, but Gengar isn't as lazy, & if Gengar can dodge enough or last long enough & realize to use its hax, it can screw over Sans in many ways.
I vote (Mega) Gengar, Medium-High Difficulty.