Or, as TV Tropes would have it, Nice Job Breaking It Hero.
I contend that most, if not all, of the bad stuff in the remaining episodes is an unintended consequence of freeing Leylia from Karla. At least from the perspective of Parn et al (even though they may not realise it).
I'm not even talking about Woodchuck being possessed by Karla, at least not directly.
Indirectly... it appears Karla's powers are at least partly dependent on the powers of the host.
And since Woodchuck has no magical ability to speak of, Karla isn't powerful enough any more to simply slap Wagnard down when he started getting frisky.
As we'll see in the days to come, there's a lot of bad stuff coming that could have been ended quickly by putting Wagnard down.
I also think that this cuts both ways. That the old hero Wort with the necessary information, and the new heroes with the strength, to take Karla down were created by the endless conflicts that Karla stage managed over the centuries.
So from Karla's perspective: Oops.
Granted that many of these unintended consequences are necessary for the ongoing storyline but I think that the message for the viewer is still valid.
And at least Parn et al do deal with the consequences eventually.
Day 1 - Prologue to the Legend
Day 2 - Blazing Departure
Day 3 - The Gender of Lodoss War
Day 4 - The Black Knight
Day 5 - The Grey Witch
Day 6 - Dub vs Sub?
Day 7 - The Desert King
Day 8 - The Sword of the Dark Emperor
Day 9 - The War of Heroes
Day 10 - Requiem for Warriors
Day 11 - Nice job breaking it hero
Day 12 -
Day 13 - The Scepter of Domination
Day 14 - The Demon Dragon of Fire Dragon Mountain
Day 15 -
Day 16 - The Wizard's Ambition
Day 17 - Final Battle! Marmo, the Dark Island
Day 18 -
Day 19 - Lodoss, The Burning Continent
Day 20 -