Finally took down Jhen. Using the binder helped so, so much. Killed it even though I accidentally missed with the first Dragonator. Thank you guide! Got him in the last 5 minutes or so. I can see how it could be a fun fight in multiplayer with people taking on multiple rolls, but I'm just not fond of the battle as a singleplayer fight.
Oh, and Plesioth, despite being a creepy fish dragon thing, has a surprisingly cute sleeping animation.
Also, I totally didn't notice that Volvidon is totally an Arzuros mod the first time around. They definitely did a good job making them fight different, but I don't know how I missed all the similar animations and whatnot before.