At which chapter can we finally digivolve into the royal Knights? Also, can anyone provide me with comments on what makes each one bad?
Chapter 19 for most of them, Imperialdramon PM in Chapter 20 post game.
They are really only monsters in Hard mode. On normal mode, they are fairly balanced. My impressions so far.
UlforceVeedramon- First monster you have to deal with that purely buffs speed all the time. If you can poison him, he can go down quickly unless you get unlucky and he uses Antidote. A lot of it relies on luck with Antidote and there are really only a few ways to beat him outside of poison since after a couple turns he's so fast that he's getting 6-7 turns for every one of your's.
Leapordmon- Pretty much the same as Veedramon, except hits a bit less hard and can't be poisoned. He also has a slower ramp to his speed up. If you can survive long enough to get his health down to the last 1/4 or so (IE, He doesn't spam his ultimate 4 times and instantly kill you), he gets locked in enhanced DEF buffing and Life Stealing, which if you resist gives him basically nothing back. Becomes easy to kill then.
Kentaurosmon and Craniamon: Kentaurosmon does the standard buff speed infinitely thing. He's fairly weak, though, and if you can either resist him with Data types or bug and resist with Virus, the fight becomes easier. It just becomes a matter of taking out Kentaurosmon before Craniamon gets you. Hopefully Craniamon doesn't spam AOE. He becomes easy once Kentauros goes down.
Dynasmon and Crusadermon: Crusadermon is the standard buff+might spam bullshit instant kill move. Dynasmon is a hard hitter, but his attack has recoil. If you bring Craniamon, you can use his damage null to let Dynasmon punch himself out. Crusadermon isn't easy at that point, and she has a bullshit full heal, but she's way more beatable.
Examon: Fairly simple fight. Has an obnoxious really strong AOE that also switches your party up, but that's about it.
Long story short, the big problem with them is that they spam BS attacks that can instantly wipe your entire squad and buff their speed so much that you can barely act.