so if mashima sticks with the 7 dragon thing then there isn't any poisen or lightning dragon.
Well i would say that their
are or
were Poison and Lightning Dragon's, or else how did the Dragon Lacrima come into existence in the first place.
From what i understand about the Lacrima's, it is a crystalline object which has the power to store magical power inside itself (along with elemental properties, if it is included as well). Thats how the large Lacrima in the ToP was created using the Etherion's power or Laxus created the Lightning Lacrima for the usage of Thunder Palace.
So that means at some point in the past, those 2 Dragon's filled there elemental power inside the Lacrima Crystals to create the Dragon Lacrima's.
Now the only question is what are the conditions for a Dragon to create a Dragon Lacrima. Can they simply create them like Laxus was able to create Lightning Lacrima's or like Urtear was create hers or do they lose there life in creating the Lacrima (i.e., either they die after making the Lacrima or after they die there magical energy gets converted into the Lacrima).
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Now on the point of Dragon Force, i think the reason it is a surprising factor for a Dragon Slayer to activate it is because i believe it is something that would only activate when the DS is facing a real Dragon (of the same element as the DS).
I mean look at the times Natsu activated his DF, one time it was after he consumed
Etherion Lacrima, and the next after he ate the
Flame of Rebuke. Both of which are extremely powerful.
So, that means for a DS to enter DF state, he needs a high amount of powerful elemental magical energy (either from a spell or an item or object).
Now, if we think about it, Igneel's flames would obviously be more powerful and destructive than even the
Flame of Rebuke or the
Etherion Lacrima. So, if Natsu were to fight Igneel it would be quite easy for him to enter DF.
Now the question of why it is a surprising factor. Well first of all to activate the DF, as i said above, a highly powerful elemental magical energy is required. So, it obvious that it would be difficult to obtain as the more powerful a spell is the more power a user would need to use that spell. So, that leaves only a select few mages of the level of say around S-Class or above. So, that decreases the amount of people who could help in activating the DF directly for the DS.
Now if we take all those powerful mages, not everyone can use a powerful spell of a certain element. I mean even Makarov can use Fire type spells, but we haven't seen him help out Natsu by give him a powerful Fire Spell to eat, that means even though he can use Fire Spells he can't use the most powerful ones (like
Flame of Rebuke) to help Natsu activate DF (i mean he should have the knowledge as to how to activate DF for Natsu).
This is also the reason why the 2nd Gen DS's DF looks much weaker than the ones of the 1st Gen DS. I mean in order to enter the DF state, they take in the power from the Dragon Lacrima inside them, which even though contains the power of a real Dragon isn't enough as the same Dragon Lacrima is being used to give the person DS abilities before entering the DF state (that means the Dragon Lacrima's power is being divided).
But in the case of 3rd Gen DS, the case would differ if what i said is true. Its because they already have turned themselves to DS before getting the Dragon Lacrima, that means the power of the Dragon Lacrima isn't divided and can help them enter DF state much easily and give them much higher level of power boost.
Well these are just my thought, which can be wrong easily. And sorry for the long post.