If you're against a whale on the last duel when you rank up a tier, you get to borrow their fancy arena background for the rank-up thingy. Probably more of an oversight than an intentional thing, but it's neat.

>>536113976
>>536117360
Thank you for the events!

>>536066015
I would recommend focusing on the current season story, main story, and past season stories. You get lots of rewards and some of the actual story stuff is pretty decent. Do your daily Forbidden Forest runs for gold (only farm echoes after you unlock legendary ones) and progress solo forest exploration as far as you can, as fast as you can (but don't stress about it too much as it is pretty level-gated anyway). Don't worry about the PvP too much; it's mechanically pretty fun in my opinion but the rewards aren't that great and due to card levelling, old players and whales have a big advantage over new people.

If you plan to spend money, the Niffler pass is far and away the most efficient thing you can buy, followed by the magic pass and the one-time 2x bonus on each tier of gem purchase. Avoid anything else unless you're whaling. Ruby Keys, Clockturn Keys, and Epic cards (only ones you will actually use) from the daily shop are generally the best thing to spend orange (semi-premium) gems on; most packs and stuff are a scam. Most of the "big" seasonal gacha events are also a scam, except for Board of Bounty, although if you really want the grand prize from any given one it's generally the only way to have a shot at it. Never ever buy gold except for the periodic Coveted Coffers event, which is very good value (save purple gems from the Niffler pass for this).

Also, join our social club (if the location isn't a problem for you — we are on the Zouwu server); the game prompts you to join one anyway so you might as well.