STOP THE HYPE:
Its not possible to gain gems from dueling against legendary duelists on gates anymore. this is the patch which flips the game from f2p to p2w.
Dude, since i made 4 KoG decks and i climb KoG lol i started leveling up to lv30 all characters and i got A LOT of gems!
Actually i have 9.5k (and at least half of them still under lv30). Just use 1.5x Exp campaing to get gems. Its around 3 days fighting with SD 3-4 times at day or using orbs its even faster.
Just play harder haha I need to say, i have a job and i dont play all day :P
You are getting almost 2k gems on this update and yet you are complaining? This is the best update ever and if you don't like it just uninstall and cya.
I didn't notice this yet but indeed this is going to be a big problem for some of us. When we have all duelists lvled up there will be no gems to be gained anymore, and that with a monthly new box and massive power creep will make this game harder to play for real grinders/veteran players like me.