These are what we call the 'YMMV items.' Things that some people find in this work. We call them 'your mileage might vary' because not everyone sees these things in the same way. This starts discussions in the trope lists, a thing we don't want. Please use the discussion page if you'd like to discuss any of these items.
YMMV: Pirate 101
Arc Fatigue: There is some of this problem in the Cool Ranch books. These were actually the first stories written when the writers thought that each world should have five books. The writers even realized that looking at the same landscape for that long would be boring so they helped mitigate the problem by adding another book that takes place elsewhere and giving the haunted skyway a major makeover to make it more of a ghost story.
Demonic Spider: Tengu Sorcerers, Radical Dogs, and Manticores can be this, due to their tendency to hit players multiple times with the epic ability Relentless. (Mojo Echo for Tengu.)
Difficult but Awesome: Flanking. Most players see it as a waste of an epic. However, in the hands of a skilled player, This is basically an extra hit that works great on companions based around building Rank 2 Relentless and hitting the opponent over and over such as Hawkules. Building Crossfire on your musketeer though just makes you a joke in PvP.
Goddamned Bats: Sky snakes in Aquila. First of all, they have first strike and vengeance strike at the same time, which although is not as good as riposte, is still annoying for players with guaranteed criticals, sneak attacks, charges, etc. The single point in relentless what sells it though.
On another note, there is the fight with Count BrastilloDe Brass. The boss himself is just annoying to say the least with him casting Rain of mortarshells on you and dominating musketeers with Rank 2 Quick Draw and in the second fight, Rank 2 True grit. (Basically Musketeer Vengeance Strike) However, It's all worth it in the end when every time you hit him, he makes the most Over-exaggerated sound that is both hilarious and satisfying.
The Scrappy: Miracle Mitch. In the recent update, now once your companions are defeated, They are put into bed rest for up to six hours at high levels. The only way to revive them early is through Miracle Mitch. The Scrappy part comes when he charges HUGE sums of gold, making dungeons much harder as you can't revive them immediately with mojo potions.
Tear Jerker: Bonnie Anne's third promotion. It tackles her family issues and immediately sends her into Woobie territory after what she had to do and what it cost her family. It doesn't help that it's really easy to get attached to her as a character due to being rather down to earth in terms of personality.
Privateers have Valor's Armor. Using this in combonation with valor's fortress can turn literally anything into a Tank.
Buccaneers have their infamous vicious charge. It lets them move all the way across the map to deliver high damage to a target and absolutely destroy their Accuracy for a few turns. After, they get an additional attack to an enemy nearby which does half damage, But can't be dodged.
Swashbucklers have Assassin's strike, which, with buffs, can nuke squishy targets. Oh, and with the right gear, it can be spammed multiple times.
The Woobie: In her final promotion, we learn that Bonnie Anne volunteers for missions at a Special Branch to fight the armada. Which is the same special branch that her brother says is enslaving their friends and family. The kicker though is that after Guy Fox escapes, Bonnie explains that he's probably going to hang for his actions. Talk about family issues