I'm not saying Jean's wifi signal wasn't important, just that Spidey shouldn't be kissing only Jean, fairness and all.
I think I found the scene and it's not really what TV tropes described:
(Incredible Hulk#31 vol 2)
Basically what's going on here is that Leader is transcending somehow, and he describes it as becoming one with
something, and is also described as becoming "pure consciousness".
So yeah, whatever's going on, he's not becoming pure thought here, and if this is the scene TV tropes described, they're not really right about what's up.
Ironically enough, I was wrong about Leader not having telepathy, he shows telepathy here, and later on in Bruce Jones' run to take over Banner's body.
Funnily enough, he was also shown the capacity to body surf in Incredible Hulk#432 (About 4 years after Jean did it in Uncanny X-Men#281~283), but it's limited to only one Gamma being (As far as I checked in that brief speed reading that is)
All of this by the way was retconned to be connected to The One Below All in Immortal Hulk (Specifically issue#34), the being he wanted to become one with as The One Below All itself, and body surfing is shown to not be exclusive to Leader and has nothing to do with his enhanced mind or telepathy, since other Gamma beings do it as well in Immortal Hulk.
So yeah, short version is, the "pure thought" stuff with Leader may not be exactly the case if I found the right scene, he was ascending somehow, fails, seemingly dies from it, and Immortal Hulk retconned it into him becoming too close with TOBA, who's only connected with Gamma beings and not telepaths.
Zdarsky's X-men/X-Men also has data pages with a theory saying that powers have the same source, just different forms of "Godpower":
https://cdn.discordapp.com/attachmen...54/unknown.png
(X-Men/Fantastic Four#1 vol 2)
https://cdn.discordapp.com/attachmen...62/unknown.png
(X-Men/Fantastic Four#3 vol 2)
Don't really care about the idea of everything having the same source though, stuff like that is what made Ultimate Universe boring, since almost everything on Earth, including most mutants, are just variations of Captain America's super soldier serum.
Wolverine himself though is an actual mutant, and he's the source of X-Gene (As shown in Ultimate Origins), and he was used as another attempt to recreate the super soldier serum, dunno how Apocalypse is connected with that, maybe he was another random mutant way before everything and X-Gene just showed up at random once every few thousand years, but I doubt Marvel was thinking that much 'cause Ultimate Apocalypse is a mess lol.