With digimon evolution rules are simple. If it makes sense it works, so Ladydevimon evolves from Devimon or BlackGatomon, because both have a logic to them. Then there are Warp, Matrix, Mutant and Slide evolution types. Warp and Matrix let digimon skip ahead, and Mutant and Slide allow them to change into a digimon of the same level.
This is one of the sexiest Ladydevimon picks I've seen.
Hikari/Kari's partner Digimon had a standard form of Adult/Champion, unlike the other kids, whose Digimon held a standard form of Child/Rookie. This is explainable by Tailmon/Gatomon's much tougher life due to be seperated from her partner much longer than the other kids.
Angewomon and LadyDevimon are both Perfect/Ultimate Digimon. LadyDevimon is usually shown as evolving from Devimon, despite Devimon usually being depicted as male. PicoDevimon/DemiDevimon is a Child/Rookie level.
I've heard theories that Tailmon/Gatomon is weaker than her level would indicate becasue of something to do with her Holy Ring (the thing on her tail).
Hikari's Digimon line (in canon) is Nyaromon->-Plotmon>Tailmon->Angewomon. Due to the dub putting an out of continuity movie into continuity (poorly), Kari's Digimon line is Nyaromon->Salamon->Gatomon->Angewomon->Magnadramon. In the original Holydramon/Magnadramon is not a canon evolution due to the movie being out of continuity.
Many fans will apply a different evolution line for a Digimon that has appeared in the series. The series itself did this with Savers/Data Squad and Masaru/Marcus' Agumon.
I'm afraid you has some confusion. Hakari's Gatomon never takes the form of Plotmon and her canonical evolution line is Nyaromon->Salamon->Gatomon->Angewomon->Magnadramon Se never takes the form of Plotmon and despite the dub forcing the first 3 movies into one the events and digimon in them still exist int eh universe of Digimon 02, it's just Diaboromon has nothing to do with the events involving Kokmon, Terrimon and their Digidestined, there isn't any link beyond both incidents involving some of the same people. How ever this is the evolution line of a Individual Gatamon, Digimon unlike Pokemon don't have real "true" evolution lines, any evolution line that makes sense is valid because digimon has a multiverse and different digimon might share a particular evolution, they may even be in the same story universe. Ryo from digimon tamers has existed in the same universe as the characters from digimon 01/02, as he and Ken from Digimon 02 fought and defeated Melleiummon with Ryo's original partner being Veemon, his Veemon followed the Veedramon path. Davis'(I forget his Japanese name) Veemon follows a completely different while the verson of Tai from one of the Manga's has a Veedramon who evolve from a Agumon (never actually stated but it came from a digivice toy so it's implied) These 3 paths are DemiVeemon -> Veemon -> Veedramon -> AreoVeedramon
Each is completely valid, completely real, completely cannon.
By the same token Tai's Agumon and Marcus' Agumon both evolve different because they are different Agumons with different partners in different universes.
Ladydevimon CAN evolve from BlackGatomon, Devimon, or even Icedevimon, because all three make sense.
finally keep in mind some Digimon have different versions of different evolution levels, or effective evolution levels. Gatomon and Blackgatomon both come in rookie and champion, Whaemon comes in Champion or Ultimate, HerculesKabuterimon comes in Ultimate and Mega.
Erm...Plotmon/Salamon DID appear in the anime, during Tailomon/Gatomon's flashback if nothing else. As for the rest, you're probably right.
Nyaromon->lotmon->Tailmon->Angewomon->Holydramon is EXACTLY THE SAME as Nyaromon->Salamon->Gatomon->Angewomon->Magnadramon, just the first one uses the Japanese names and the 2nd uses the dub names. Plotmon can also be romanized as Protmon, and is short for Prototype Monster.
Plotmon/Salamon is the white puppy creature with the gold Holy Ring styled collar.
Well their's the confusion Plotmon IS Salamon so both are the extract same canonical evolution line.
Digimon's flexibility's with evolution really is a great feature especially in the games, I loved the Digimon DS games for that reason, some rookies have 6 Different megas, Agumon for example had BOTH the original and DATS lines.
Yeah, and it means you can have different Tamers with the same Digimon whose main line is different than previous seasons (one of my fan Tamers is a wonderful example. His V-mon's main line goes to Airdramon rather than XV-mon or Veedramon)