Fairy Tail !!!!!! :)

I'll get to that but i just wanna ask express my theory on something i think a lot of people might be mistaken about. Just how much of a power-up is the LFD??. The LFD is weaker now??. Is LFD still a power-up? Erza is stronger than the LFD??.

Now what exactly is the LFD, the Lightning Flame Dragon, a state achieved when natsu took in Lightning based magic. and fuses Lightning and Flames. If Natsu achieved the LFD by eating laxus magic, then why didn't he achieve something similar when he ate etherion or Jellal's magic??
The logic answer is, Etherion is simply a mass of etherano so its reasonable...