Patamon's power is to become a massive Marty Stu and solve the plot whenever necessary, hence Angemon (and his higher forms).
He's not exactly a Marty Stu when he dies the first time he Digivolves to Angemon. Or how he doesn't kill Piedmon as Magna Angemon, single-handed.
Early in Digimon Adventure, Patamon asks T.K. what a Guardian Angel is. Patamon takes a shine to the idea and decides he wants to be T.K.'s; given the nature of the Digital World and of Digimon, it's not an extraordinary stretch.
The Seven Great Demon Lords. Why only half of the group is named after their counterpart in the seven princes of hell?
For the same reason Valkyriemon, Harpymon and Callismon, male digimon, are named after female figures, the angels appear as winged humanoids and Sakuyamon is a fox miko instead of a mountain goddess?
(Angels appearing as winged humanoids is really common)- Well, it is weird because half of the group is named after their counterpart and the Devas, the Olympian Gods, the Holy Beasts and the Three Great Angels followed a Theme Naming.
Why is Greymon called Greymon? He's not grey. He's orange.
Following the digimon wiki, grey, beyond the color, means old or ancient. He's a dinosaur. Do the math.
Grey is a corruption of Great. Greatmon would sound silly, so Greymon.
Digimon are, at least in some continuities formed from stray bits of human data that aggregates, or something along those lines. Point is, human data is at the core of their being, and the type of data almost certainly affects their nature. So, what is the Watsonian reason for there being so few pornographically-derived digimon? The Doylist reason is bloody obvious (kid's show), but what's filtering that data out from digimon formation in-universe?
Digimon may be able to choose their appearance and prefer not to appear like that. Also, how WOULD they appear? More abstract Digimon are higher level. Further a Digimon's appearance is normally based on creatures/people/Gods etc, you wouldn't expect a Digimon to represent a concept or sex act. And finally Digimon have blue and orange morality possibly also making them disinterested in what humans find interesting.
It differs per setting. In adventure, the world seems to have a special connection to children and is connected to the real world through some sort of dream dimension, so its probable a lot of the digital world has been shaped by the thoughts of pre-pubescent children. Plus, the final arc of zero two implies that the digital world may have drawn from a specific computer game, which we see Oikawa playing. In tamers, that explanation is canon, with the digimon based on a franchise aimed at children. No clue where the porno-monsters are in Savers though.
Could be argued that since Digimon are based on stuff floating around the internet they appear as humans, gods, animals etc because they have creative sterility always being fed the information and appearing based on what they find. This could explain why the Digimon heirarchy is based on angels and demons, Yggdrasil etc since instead of them simply being concepts or figures but without the significance humans place on them they emulate what is myth and legend in the real world. Digimon are certainly never shown to have any sense of religion and yet angel digimon are frequently leaders or rulers.
I've always been a little confused by Warp Digivolving. So this allows the Digimon to skip levels (or at least rapidly progress through a number of levels), but is it specifically always for Rookie to Mega? For example, could an In-Training Warp Digivolve to Ultimate? Or a Baby to Champion? And is it necessary? For example let's say in season one, Agumon wanted to Digivolve to Wargreymon but is already in his Ultimate form. Would he have to de-Digivolve first or could he just Digivolve straight from Metalgreymon. Speaking of which, let's say Metalgreymon did Digivolve to Wargreymon, would it be regular Digivolving, or Mega Digivolving like Paildramon to Imperialdramon? What sets Mega Digivolving apart from regular Digivolving?
In rough order from my guesses? Warp digivolving seems to be reserved to Rookie to Mega from Adventure and Data Squad. I'd say basic de-digivolving would get Wargreymon to Greymon, like in the Digimon World DS games. Mega Digivolving I think is unique for Paildramon, since he's a DNA Digimon. Fusion digimon might not be able to digivolve at all when combined. The Mega Digivolve would bipass that rule.
Warp Digivolving is basically level-skip Digivolving. In Adventure, and more specifically, according to the Adventure novelizations, there are different kinds of evolution. Basic Digivolving (Evolution) simply has the digivice call down some data from beyond the Digital World itself to push the Digimon to Champion (Adult). Digivolving to Ultimate (Super Evolution) is really the same thing, but uses the crest as a catalyst to stream a huge amount of data into the subject Digimon. Warp Digivolving/Evolution is basically level-skipping. In Adventure, Taichi and Yamato directly fuel their partners with a huge injection of power that causes them to leap all the way to Mega from the child stage, and they do it only under those circumstances because otherwise the Transformation Sequence wouldn't make sense. In theory, no, they don't have to be in Rookie form before jumping to Mega; Ultimate Evolution/Mega Digivolution (movement directly from Ultimate/Perfect to Mega/Ultimate) is not reserved to Imperialdramon (Angewomon uses it in the third movie, albeit that's not exactly canon); but again, they only have one Transformation Sequence to work with.
Savers changes the rules a little bit. Here, Warp Digivolving is actually Perfect Evolution, which automatically makes the given Digimon Perfect/Ultimate/Level 5, no matter what its previous level. In Savers, achieving Level 6, regardless of the original level, is always called Ultimate Evolution; in the dub, they call it Double Warp Digivolution, for whatever reason. Possibly not to confuse people with using the same name for different Transformation Sequences.