Elemental Chest Frequency - days tracking and results > estimated between 4 to 16 days

[SamMe]

Yes
Legendary Tome of Ascension (added chance in V44.1)
Legendary Tome of Experience (V44.1)
Legendary Tome of Golden Emblems (V44.1)
Epic Tome of Golden Emblems (added chance in V45)

No
Epic Tome of Experience (V44.1)
Trainer Troops (V44.1)

Version 45 Release Notes & Status

Status 2022-01-26T10:36:00Z (UTC): We have now started the rollout on both Android & iOS. Release Notes [NEW & UPDATED CONTENT] Soul Exchange 2022-02-28T07:00:00Z (UTC)→2022-03-02T07:00:00Z (UTC) The Soul Exchange is a recurring, limited-time event in which players may trade in a number of Legendary Heroes to obtain one specific Legendary Hero from a given pool of 15. Choose wisely — an exchange can only be made once per event! War of the Three Kingdoms (Global Beta) 2022-02-07T12:00:00Z…

Version 44.1 Release Notes & Status

Status 2022-01-10T09:20:00Z (UTC): We have now forced the update and enabled Tomes and Trainer Troops as in-game rewards. Release Notes To kick off the new year, we’re improving rewards all across Empires & Puzzles! In our last update, Version 44.0, we addressed some of our top players’ feedback by reworking how Limit Break Materials are awarded in Alliance Quests, Alliance Wars, and Raid Tournaments. Loot consistency at higher tiers should be much better under the new system. With Version …