Not necessarily sure if you need a max SpA Espeon to start with in this category, but it certainly helps for segmented. Ideal nature is Mild, as the low Defence encourages more attacks to go towards Espeon and leave your Croconow/Feraligatr free to damage enemies. -SpD hurts for something like the Shadow Mantine fight, so I wouldn't consider Rash, and Espeon starts with high Happiness so you can get a lot out of Return on high SpD/low Def enemies so I wouldn't like anything that reduces Atk either.
As for Croconaw, I got a Rash natured one for my current run. Mild will hurt it less, as it already has a high Def stat to play with, but I proved Rash can work, provided you get some luck in the Lab sections with all those Electric types to deal with. The real issue comes to snags, and the best time to take them.
You can have as many as 3 opportunities for a particular snag, if you count the post-Evice section of the game, which you would for 100%. Time ends when you get the final snag, on Togetic, so you would aim to get all of the other 47 snags before then. My route for the snags considered the exp you would gain from the fight, as well as the replacement for the snagged Pokemon, as well as the position of the Master Ball in the run, which you would obvious use the Ball-Dupe glitch to get as many fast snags as you can.
Before the Master Ball, I wanted to get as few snags because anything not snagged by a Master Ball obviously takes a bit of time. I think the only one that comes close outside that was the Makuhita snag, as it has a 220 catch rate, but I found a 3 turn strategy for Croconaw snag that was fairly consistent: 1st turn: Confusion on Grimer, Bite on Spoink; 2nd turn: Confusion on Croconaw, Bite on Spoink. 3rd turn: Ball-Dupe Great Ball (you buy one from the Outskirt Stand); proving a surprisingly consistent level of snag, guess they wanted to make it fairly easy to get the GSC starter. Catch rates in general seem to be more generous than the handheld games, even for the things you would expect to be tough like the Legendary Beasts.
Before this post gets too detailed and erratic, I should stop for now. Any ideas to help improve this type of speedrun would be appreciated
