Which covenant should choose Druids in Shadowlands?
Covenant for Balance druid in Shadowlands
Currently Kyrian is outperforming all covenant options for Balance Druid in all forms of content. While Night Fae and Venthyr are solid alternatives, they aren't superior to Kyrian in any way currently. It is worth noting that Kyrian is weaker in solo content, but generally speaking these rankings are aimed for a Raid or Mythic+ environment, not solo content
Covenant for feral druid in Shadowlands
Overall, the covenant abilities appear to be extremely balanced for Feral, but as with Balance, Kyrian does have a very slight edge in all forms of content currently. That said, Venthyr is a really strong alternative, especially for AoE, and while Convoke the Spirits isn't simming properly for Feral atm, it appears that it will be a strong option for ST.
Covenant for guardian druid in Shadowlands
While I'm not going to change any of the rankings for Guardian, as I feel this still accurately reflects the balance situation atm, there are some important details I want to discuss. For Single Target, the best choice by far is currently Necrolord. Guardian has quite a few DoTs, so this ends up working out quite well for them. On AoE, the best option is Venthyr, since getting out more thrashes/swipes in your Berserk window is obviously pretty good on multiple targets. In both cases, Kyrian is your second best option, and it's also quite good for survivability. If you've followed my content at all you probably know my stance on building survivability as a tank, BUT in this case you could justify picking Kyrian since it's already VERY close on both forms of damage. When you consider the fact that it's a well-rounded DPS pick along with the large survivability it grants, it seems like a very enticing option. At the moment the only covenant that has no redeeming qualities for Guardian Druid is Night Fae.
Covenant for restoration druid in Shadowlands
Very little has changed for Resto Druid over the course of the Beta. By all accounts, Night Fae is still by far the best option. While the buffs to Kyrian have helped it not be completely useless for Resto, it's simply not as good as the other options. As for Venthyr, it's currently not performing as well as Night Fae, but this might change over time as the average ilvl increases. Necrolord is a relatively solid damage choice for Restos that catweave in Mythic+, but I feel this is a really niche use case for the majority of the playerbase, and generally speaking you'll still get more mileage out of Night Fae.