Dragon Boy 2 RPG

"Dangerous bugged items:
Confirming that the three slot Rune Blade and the four slot Dragonslayer sword are broken and will become stuck in your inventory permanently. I recommend filling your entire inventory with fruit/vegetables once you get near the end of normal difficulty (and for the entirety of Hard and Extreme modes) so you can't accidentally pick these up when clicking to attack. This is because these items are very cheap and easily replaced, useful, and you won't feel bad about dropping some of them in order to pick up loot you ACTUALLY want to keep. The various golden/unique named versions of these swords are safe (such as the Noble Marine Dragon Slayer), it's only the generic max slot versions that are bugged. There is no way to remove them OR equip them once you pick them up, so DO NOT TOUCH THEM.

Bugged dragon:
The Ice dragon is broken, which is a shame since I like how it looks. Once it reaches adulthood/Level 7, it will NEVER attack enemies again, even though the juvenile stage DOES shoot a single ice ball just fine. Utterly useless, do not use an ice stone on your egg. Otherwise, most of the other dragon elements are all perfectly serviceable and useful.

Helpful bug:
Once you're on Hard or Extreme difficulty, you can access the second and third tier of elemental stones, respectively. If you have a full inventory and click on a stone that a monster has dropped, it will turn into a random tier (of those available in your current difficulty setting) stone of the same "family" of element. I.e. clicking on a fire stone might turn it into a sun stone (Hard) and/or a Death stone (Extreme). It might also turn back into a fire stone, so just keep clicking a stone until it becomes the one you want! This doesn't work on stones you've already picked up and then dropped on the ground again.
The stone "families" are:
Fire->Sun->Death
Ice->Moon->Zombie
Lightning->Plasma->Life

Tips:
Use an endgame character on a harder difficulty to farm stones for a new character and leave them in the treasure chest.
You can set stones in an item and then remove the item and place it in the chest, and the stones will stay set. BUT, if you talk to the shopkeeper AT ALL, all the set stones will be removed from any items in the chest. The items in your inventory will be safe. This is a good way to remove the stones from your items so you can put DIFFERENT stones in them.

For a new player, I would recommend Arazec with a fire or lightning dragon, since she is probably the most powerful and "safe" character at low levels, and you will have an easier time progressing through the game and finding better gear/stones for your other characters. Umbra lags the game with a full party, and Atal has no ranged attack options.

You can find higher powered monster spirits on Hard/Extreme mode with one character and put them in the chest for Umbra to use. This way you can use a small number of POWERFUL monsters and hopefully reduce the lag issue (and enjoy sweeping through early levels). You can also use these high level spirits to quickly level up a different character's newly hatched dragon! Dragon maturity is based on its level only. It can't grow past certain levels until you beat the game, though. It will still gain EXP, though, and will level up once you beat the game, assuming it has enough EXP.

If your dragon is running low on HP during a battle, such as the final level, you can feed it a monster spirit from the Party menu to completely restore its HP. This doesn't work if it has already died.

As mentioned by other commenters, the Death dragon does percentage based damage and can be difficult to kill things with. I would recommend pairing it with Umbra or Arazec so you can finish enemies off with a ranged attack of your own.

The most effective dragon types for quickly sweeping through large groups of enemies are probably Moon and Plasma. Life is probably the most overpowered dragon in general because it can heal the player while damaging enemies"