Bears hibernate a LOT. You have to be ready when they do wake up, though: You might get 1 or 2 Bears a week for a few weeks and then nothing for months. Stockpiled spell frags & blueprints/diamonds are the key.
In terms of artifact availability, this is what I see happening. I could be misunderstanding the process, but:
Random Number Generator (RNG): Nickname for the various algorithms that select prizes, craft recipes, hit points in fights, et cetera.
RNG pool: The potential items that the RNG has to chose from in any given situation.
Daily M.A. Rotation: The set of 5 crafting recipes that appear in the M.A. every 6 hours automatically. Additional Daily Rotations can be 'purchased' with Sips of Clarity. Each of the 5 slots specializes in different types of recipes.
Not all artifacts are available to the RNG on any given Daily Rotation
. The Daily Rotation's RNG pool changes as part of a
Grand Rotation. Grand Rotations happen ~6 weeks, are announced by Inno in advance, and affect the Spire as well as the Magic Academy. Grand Rotations appear to include Planned and Randomized aspects.
Planned Grand Rotation Items (Planned GRIs) may include things like bug fixes & brand new prizes/recipes but are mostly about which artifacts (Spire/M.A.) & Evolving Building bases (M.A. only) are in the various RNG pools for that Grand Rotation. Artifact selection is based on an historically-predictable schedule (discussed later) and is the same for all players in a given market (i.e., all Beta players, all U.S. players, etc.).
Based on personal experience & forum anecdotes it seems like some craft recipes appear (and disappear) in unpredictable clumps. My hypothesis is that some recipes are
Random Grand Rotation Items (Random GRIs). Rather than being available in the Magic Academy's RNG pool all the time, Random GRIs cycle in and out as part of the Grand Rotation. In other words, Random GRIs have to go through
two RNGs to appear as a crafting recipe: First they have to be selected by the Grand Rotation's RNG, then they have to be selected in the Daily Rotation's RNG. And, since RNG results are unique for each player, Random GRIs vary from player to player.
Putting all the pieces together, this is what I think is the process that Artifacts go through*:
1) Artifact "A" and Evolving Building "A" are introduced in a new Event as prizes.
2) 1-3 months later, Artifact "A" is available as a Stage Prize in a Fellowship Adventure. Additionally, from this point on:
2a) Artifact "A" and/or Evolving Building "A" may appear in a later FA (usually within a Sorcery).
2b) Artifact "A" and/or Evolving Building "A" may be available for cash purchase.
3) Approximately 18 months after the original Event, Artifact "A" becomes part of the Grand Rotation in a specific sequence. Evolving Building "A" also becomes part of the G.R., but only if a player doesn't have it already.
3a) Grand Rotation #1 - Artifact "A" is a Planned GRI in the Spire's RNG prize pool. Evolving Building "A" is a Planned GRI in the Magic Academy's RNG recipe pool (1st slot).
3b) GR#2 - Artifact "A" is unavailable. Evolving Building "A" is unavailable.
3c) GR #3 - Artifact "A" is a Planned GRI in the Magic Academy's RNG recipe pool (5th slot).
3d) GR #4 & onward - Artifact "A" is a possible Random GRI in the Magic Academy's 5th slot, along with all older Artifacts. Evolving Building "A" is a possible Random GRI in the Magic Academy's 1st slot, along with all older Evolving Buildings.
4) Artifacts & Evolving Buildings go through this process in same order in which they initially appear (except possibly for steps 2a & 2b).
It's a lot easier to follow in action than it is to describe, IMHO. And everything about Random GRIs is guesswork & hedgery on my part.
*The process needs a clever name, but I've got nothing.