You can either synthesis them, get them in a trade, or get a couple as reward monsters after the game.
Sadly you can't scout rank S - X monsters , but you can synthisize them you can get a Zoma (rank X) by synthesising a malroth (rank S) and a wight king (rank S) to get a rank X
great dragon + bone baron = black dragon any rank A monster + any dragon monster = great dragon grim rider + mohawker = bone baron
After completing the game you can synthesising the incarni with a certain rank of monster to get the children form back
You Go into the moon temple do the same thing you done to get the sun template to get the moon template then the mirror will transport you to the nexus after defeating the Great Dragon (Rank A) your incarnus will turn into a diamagon
It is actually quite easy to do. You fuse a set of 2 Mischevious Moles (Rank F) and a set of Night Clubbers (Rank S) to get the pompous but powerful Don Mole True, but THIS IS the easiest way. Sythesize four Michevious mouls and then get a Buffalore and sythesize them!
(jamirus + dingaling) (frog face + wailin' weed) (any demon + any rank A '6')
Monsters that are synthesized by using high-level monsters with high ranks (Rank S, or A) usually produce the strongest results. It requires a lot of patience due to the amount of leveling involved, but it also needs the highest ranks so there is some planning required. There are walkthroughs for the game, but it is ultimately more fun to play through the game yourself instead of cheating by looking at the answers page. The strongest monster is either Dr snapped, dragovian lord, wildcard or ace of spades, but dragovian lord tends to be considered the strongest.
The best team is Atlas (finish rank X to get miracle mace to heal after a hit) Drakulard ( cast kabuff to strengthen defence and have kerplunk to get any KO'ed members back) Zoma ( to cast disruptive wave to knock off any defence type attacks to your opponents)
If your talking about the quest, you kill wverns and Water draconians. If your talking about dragon slayer class, that's a rank and if you want to rank it up, I suggest undead pirates
Beat the storyline. Then, beat solitaire's challenge (rank X battle arena, complete advance test, defeat solitaire) and you will get a key. Head down to the sewers and use the key on the door.
Well, I am not sure if this helps or not, but get strong monsters. If you are trying to beat her with three rank A monsters, that is still not good enough. I suggest a Black Dragon Rank S (Great Dragon+Bone Baron) You can look up on Wiki answers to find out how to get a Bone Baron and a Great Dragon. That could be the muscle of the team. The healer, another rank S, could be a Malaroth(Demon-at-Arms+Buffaglore) The third member of the team could be the Icuarnes or some monster strong. If you want really strong monsters, collect 100 monsters and talk to the man in Solitaire's office. He will give you a Liquid Metal Slime. I forget, but somehow I got a Metal King Slime from one of the people in the office.
By slaying Der Gib at S Rank or Valgirt Nedlog at A or S Rank