- LATC is a Balance Legendary. It only counts against Balance spec for the sake of BLP and obtaining other legendaries (rule of thumb: If it's on that spec's Legendary List [check the Adventure Guide Loot section], it only counts against that/those specs. For Druid specifically: Ekowraith, Prydaz, and Sephuz are all 4 specs, Cinidaria is all specs but Resto, KJBW [DPS Trinket] is for Balance and Feral, and Luffa Wrappings is for Feral and Guardian. All other legendaries are only 1 spec).
- LATC does a twin Moonfire for every spec.
It also does proc off of the passive part of Guardian's "Galactic Guardian" talent (and obviously casting it does a twin Moonfire as well). The only benefit LATC doesn't carry to the second Moonfire is the +400% direct damage of GG procs (the primary target takes 400% increased damage, the second target doesn't get that benefit).
- LATC prioritizes targets that does not have the Moonfire debuff and is within 20y of the original Moonfire target. Both the secondary and primary targets must have already been in combat for the second Moonfire to trigger. If all targets within 20y of the primary target are in combat (and the primary target is also in combat too), then LATC will prioritize the closest target. LATC does not factor the duration of Moonfire into account, it will only prioritize targets without Moonfire before just hitting the closest target with it.
- LATC does benefit from Wax and Wane (both targets take up to 125% increased Direct Damage from Moonfire), but neither LATC nor Wax and Wane changes your rotation. The only thing LATC incentivizes you to do as a Boomkin is to consider Moonfiring ~4-6 targets instead of only ~2-3.
- Overall, LATC is a mid-tier legendary that is really good in M+ and low-to-mid target cleaving. It's also a very solid DPS choice for Guardians as Moonfire is a huge portion of Guardian's damage.
This should hopefully answer any and all questions you (or anyone else) has regarding LATC