[Trexmaster]

I'm not 100% sure if it's intentional or not, but as it stands (as of v 2.00.6b) monsters mercenaries don't gain any skills they'd have gotten from being a higher level (Fire and Earth, Dadum, Accel, etc), nor do they retain any skills they had that were randomly applied from those they could potentially receive due to their type (Riposte, Protect, Guard, Ryemei, Sear, etc).

There's also the fact they don't retain any mini-boss bonuses or Aspects/Fated Enemy, but that'd probably get out of hand if they retained those.

So I'd suggest monster mercenaries start carrying over the skills they had when captured, if possible.

At the very least I'd like it if monsters kept the skills they're supposed to have at higher levels, like Firespitters being able to deal fire damage to other fire mobs(Fire and Earth).

[Akaiger]

+1 yes, please. My lv 75 wings of fire had Ryemei before capture, and now, all it does is spam its fire skill on Flamespawn like a jerk.

[K Peculier]

I too wish to collect towering specimens. Yes agreed.