I played dis game on Facebook last 2013 L0L

dude i have 3,684,271 xp

They give A LOT of free mythicals which is good BUT since most of them are worthless (let's be honest they are) then it's not very helpful. You may need to gather 100 - 200 mythicals to build a tier 1 build. The solution is not giving more mythicals but just buffing and nerfing so that there is more balance in the game. :p

Regardless the more u play the better you get in this game, no question. More EXP, more money, more fusion, more items, more free boxes. The mechanic of giving veterans more perks would only reinforce this trend. It's not even remotely OP as it would take a very long time to unlock and the rewards on this thread are rather meager. :/

Another (but very similar) idea would be to distribute the rewards for amount of time playing. Like every 6 - 12 months, the account gains some free gold/mythical boxes and/or tokens. It would not only give an incentive for players to stay and to play more to unlock it, but also gives a very good feeling of being rewarded which keeps them playing more and not getting bored or frustrated with the game, especially for free to play players.
So I think this a serious idea that deserves some consideration.

Well I think it is decided that after 500000 xp one random mythical.

awww, why 3+ years???
ive been playing since early 2015(a bit over 2 years), how am i not considered a veteran (ive seen 3 different campaign formats, at least 5 different UI's, and gathered a collection of mythicals that probably totals at least 150)

extending the limit of experience bar doesnt work?