Good guide overall, but I've got a few gripes.
-I'm not sure exactly what each section title is in reference to: does it refer to your arena level? If so, I feel that some of the later stuff is more relevant to silver/gold than plat (upped cards, FG farming, shards are all relevant topics to a mid-level player). If not, it seems to just be an arbitrary scaling of player experience, which seems unwieldy.
I used the 4 stages of bronze, silver, gold, plat as a way to scale beginners, amateurs, skilled players, and veterans. It doesn't correlate to the player's level, but I felt it was a logical progression since those are the 4 terms that Zanz had used in game.
-Farming ai3 - you have farming decks listed, but seem to lack any place that says "farming ai3 is decent for getting electrum/cards with an unupped deck"
The closest I could find was "Now that you're familiar with the basics of deck building, build yourself a nice rush deck to take care of AI3." I'm not sure if I did mention AI3 was the most efficient, but I'm pretty sure I did. It's been a while since I wrote it, but I'm pretty sure that I've said AI3 is one of the best nonupgraded places to grind.
-A graboid rush is really good imo for the "bronze" section. You introduce rarespins in silver, but don't mention upped cards/shards (which are directly relevant and can be used to improve decks)
I think I have "Sadly, I really can't recommend any specific decks for arena since it always changes, but a fast rainbow could do pretty well in the Bronze and Silver leagues. A good arena beating deck should have enough flexibility or enough of an edge in speed or control that it truly shines and can counter a variety of different deck archetypes." I'm pretty sure any decent rush deck is good in bronze/silver even without rares or upgrades.
-A section on the strengths of rare weapons would be nice, since you seem to have skipped over that.
The actual weapons that is chosen doesn't really matter, just like the beginning element. Even if I were to say that Arsenic or Vampire Stiletto is the best, I don't want someone with a mono fire deck going for one of those and changing their entire playstyles and decks to make use of it.
-Grinding FG's should be introduced earlier (Limitless Speed would fit in Silver/Gold level). You skipped over the last quest (killing an FG)
When I wrote this, I didn't really write it in a chronological sense. I wrote it in a sense of sliding difficulty. It's also not that bad, as I introduce it in the section right after I teach how to build decks.
-OTK's for ai3 is overkill. You shouldn't really be worried about stuff like miracles or mass healing in ai3 (it's a good topic to introduce, but more as a vocab term imo
I put the OTK in the deck archetypes as a vocab term as they are a legitimate type of decks to build. 100hp ones aren't that practical, but I included it for fun. (The game is supposed to make the player have fun)
Well I'm glad to see that it's aged quite nicely in half a month, even if 1.4 is coming out soon. I think the majority of its tips (such as deckbuilding) can stay as the actual game mechanics of battles haven't changed. Some images are a bit bork, but overall, this is just as good as when I first wrote it. If I've even helped one newbie by writing this article, then my goal is complete: a comprehensive guide involving originality and creativity about the game.