this may be a spoiler for some viewer discretion is advised.
i see a lot of people don't believe in Grays power but let me tell you something Gray is very strong now the moment Gray got his ice devil slayer magic he shot up in strength and was stronger than both Natsu and Erza.
Gray PROTECTED both Natsu and Gajeel Natsu noticed his power and thats the main reason Natsu took his 1 year training journey Reasons: Gray Zeref
and i see a lot of people saying that Gray is weak because Natsu beat him in the episode with the crazy dragon lady but that just makes them even because Gray beat Natsu when they were kids and after all the years Natsu finally got him back in that episode even though Gray lost on purpose
my son Gray is not weak most of yall just sleeping on him because literally all the slayer magic strength as a whole goes from Devil Slayer God Slayer Dragon Slayer its just the individuals that are strong so im not saying Natsu is the weakest ._. he is the strongest
now out of the three the strongest goes from Natsu Gray Erza yes Erza is last if you're not caught up with the manga don't complain even Erza realized she will soon be the weakest out of the three of them