Thats just horns nothing special....Alegria had horns too but not the thorn curse....
So now everything what a character says makes also sense and/or is the truth? Nice, then we have nothing in the whole manga that doesn't make sense anymore. What a relief
Then this is also true, because she said it. Don't complain it anymore, it's now a fact and it makes also very much sense because a character said it. Just accept it.
Same with this
He said it so it's truth and makes sense.
So now that we have nothing to complain anymore, we all can enjoy the manga.
I like it btw that Lucy, Erza, Laxus, Elfman, Mirajane, Wendy and Natsu are now on the same level like Acnologia maybe even higher, because the CB are stronger than the DG and the DG are on the same level like Acnologia.
I can't wait to see how Gray and Juvia will reach this level soon too when they defeat dragon Anchor.
So now seriously, she never showed any curse from the other Tartaros members besides Seilahs and this is a pure FACT. It doesn't matter what Mirajane said, because the facts are different. Not to mention that many members were already dead during that time, Mard Geers book was even destroyed from Zeref himself, how should his soul be still there? Also, what does she even mean with all souls of Tartaros? Tartaros had many demons, also many 0815 members, where is the proof that she literaly consumed all Tartaros members? And if this is the case, why she never used their curses? Just because?
Also, where is the proof that Mashima planed this since the Tartaros arc? If this would be the case he would have already used some of the curses but he didn't what proofs more that he just add the thorn curse and never planned this. It can also be called a retcon, like many other things too not only in FT but also in other shonens.
It's cool that she can use it and maybe other curses too, I like it, but it just doesn't make sense and that in many ways.
Things like that destroying previous things, battles, etc in the manga like her battles against Jacob, Acnologia, Lucy, Skullion, Daemon and even against Scissor/Levia. Because if she can really use all powers, many battles would be different and would be better.
She doesn't even need the others, just the simple fact that she can now use the thorn curse a powerful curse (Mard Geer best example) could have change so many things and now these things doesn't make sense, just because she never used it.