Monster Evolution Guide
One of the biggest pains in the rear of Dark Cloud 2 is having to level up Monica's Monster Transformation in order to make it viable. It's not required for any aspect of the game outside of collecting Medals luckily. The first version of each monster you get is nearly useless which makes acquiring Medals that require it really difficult. I have found a pretty good way to cheese the leveling of each transformation! What you'll want to do is kill the monster with Monica and then switch to your transformation to collect the ABS.
Each level only requires 100 XP and the levels start to really slow down as you get higher in level. The first Rainbow Butterfly Woods and Starlight Canyon both gave me a decent amount of EXP until level 10 then I could only get EXP from Ocean's Roar Cave and onward.
There's more to leveling up a monster transformation too than just killing mobs and picking up abs. Every 25 levels they can evolve into a stronger form and when they do they'll give you an item. Before we get to that, the levels your monster will gain a new level is 26, 51 and 76. To upgrade your monster when it reaches one of these levels go to your Badge Box and inspect the badge to level it up. A picture of me doing this can be seen in the picture to follow.
As for the reward, the first two form upgrades you'll be rewarded with a Monster Drop. The final upgrade you'll be rewarded with several Gemstones. More on this at the bottom of the page.
After you level up and acquire your Monster Drop you'll be able to switch back and forth between the original monster and the leveled up one. I don't really see any reason you'd want to play the crappier monster but the option is there none the less. Before I discuss the various rewards for leveling up a monster let's look at all the different categories of monsters there are and the different evolutions of those categories.
Level 1: Wind Gemron
Level 2: Ice Gemron
Level 3: Thunder Gemron
Level 4: Holy or Fire Gemron
Level 1: Sewer Rat
Level 2: Ram or Beach Rat
Level 3: Savage Ram, Castle Eater and Hunter Fox
Level 4: Bandou, Death Mouse, Smiling Wolf
Level 1: Bomber Head
Level 2: Triple Cracker
Level 3: Danger Bomb
Level 4: Sweet Dynamite
Level 1: Pixie
Level 2: Sylph
Level 3: Faerie
Level 4: Imp
Level 1: Froggy
Level 2: Geron
Level 3: Moon Goyone and Gamal
Level 4: Mariner and Putos
Level 1: Himarra
Level 2: Balalla
Level 3: Stormflower or Mallone
Level 4: Mandora or Scarecrow
Level 1: Club
Level 2: Diamond
Level 3: Heart
Level 4: Joker or Spade
Level 1: Skeleton Soldier
Level 2: Hornhead
Level 3: Master Jacket and Whitebeard
Level 4: Rare Jacket and Oyakata
Level 1: Baron Balloon
Level 2: Flotsam Balloon
Level 3: Count Balloon and Guardia
Level 4: Duke Balloon and Dark Keeper
Level 1: Spider Lady
Level 2: Shiva
Level 3: Miss Gourgon and Spider Lady 2
Level 4: Bambamchoo and Mrs. Gourgon
As promised let's talk about the Monster Drops! Monster Drops are unique items that you get when you reach a new evolution for that Monster. Once you reach the final evolution you'll be given a more powerful Monster Drop as well as gemstones. The bad news is getting to the final evolution is extremely time consuming. As aforementioned Monsters level quickly at first but they start to get less and less XP as they get higher and higher in level.
Combine the fact that they suck so terribly bad and thus are almost completely useless I would like to disuade you from spending a lot of time leveling these up. It will take you most likely 5 - 6hrs of constant grinding to reach max level with a monster and the rewards just aren't good enough to warrant it unless you're a major completionest. Or... writing guides like me!
Below is a picture of the first Monster Drop i got for one of the badges. I would say a I spent a total of an hour and a half specifically leveling the monster up for that reward and the level 25 Balalla I have is still unable to successfully clear Starlight Canyon's Monster Transformation prerequisite for a medal.