Night Fae
Blessing of the Seasons is an ability that buffs a friendly target, rotating through the four seasons as you use it:
Blessing of Summer,
Blessing of Autumn,
Blessing of Winter, and
Blessing of Spring. In addition to providing a decent damage buff from
Blessing of Summer, it's an ability with decent utility as it can also be strong to help out a healer if necessary with
Blessing of Spring.
Blessing of Summer doesn't quite end up lining up with Ret's cooldowns very well since it ends up being a 3 minute period between any specific season before you're able to cast it again - since you need to wait through four 45 second cooldowns for each season - and Ret's biggest damage cooldown,
Avenging Wrath, is a 2 minute cooldown. (Even if this period is reduced by
Blessing of Autumn,
Avenging Wrath's cooldown is reduced at the same rate so there ends up being the same gap between the cooldowns either way.) However, you are able to use it to buff another player's damage instead if they have cooldowns available at the time, which mitigates the awkward cooldown timing a little bit. It's also important to note that while
Blessing of Summer does Holy damage it doesn't actually get buffed by Ret's
Mastery: Highlord's Judgment, so there's no downside to using it on whoever will do the most damage during its duration anyway. The potency conduit for Night Fae,
The Long Summer, increases the duration of
Blessing of Summer.
Soulshape teleports you forward a small distance and increases your movement speed for 12 seconds, but using most abilities will cancel the
Soulshape form. This is still a powerful option to have for Retribution, since our only baseline mobility option is Divine Steed, and there have been significant mobility issues for the spec since the dedicated mobility talent row disappeared at the beginning of Legion.
Venthyr
Ashen Hallow is a targeted ground effect that does ticking damage to enemies inside over 30 seconds, allows
Hammer of Wrath to be cast while standing in it regardless of the target's health, and buffs
Hammer of Wrath's damage. With
Ashen Hallow having a long duration for an unmovable ground effect there can be situations where enemies are moved out of (or die) before the full duration is up, and its 4 minute cooldown can make it very costly if it's used in a situation where you can't get full damage out of it. However, the ability is still numerically very strong and it scales reasonably well with extra targets, although its ticking damage is reduced past 5 targets. Venthyr's potency conduit,
Hallowed Discernment, increases its ticking damage on the lowest health target.
Door of Shadows is a 1.5 second cast that teleports you up to 35 yards at a targeted location. Similarly to
Soulshape, any ability that offers additional mobility to Retribution is likely to be a strong choice for any PvE content due to the lack of options for the spec otherwise. Although its cast time is a drawback, in most situations you'll need to use it you will be able to adequately prepare and start casting it early if you know you'll need to use it for a specific mechanic.
Kyrian
Divine Toll is a 1 minute cooldown that casts
Judgment on up to 5 targets within range. The
Judgments cast do double their normal damage, the
Judgment debuff is applied to any enemies hit, and you gain 1 Holy Power for each
Judgment cast as normal. The baseline single target damage for this ability is pretty weak relative to the other covenants, but it improves significantly with the Kyrian potency conduit,
Ringing Clarity, which provides a chance for it to cast its empowered
Judgment four times on your primary target instead of once. For AoE situations, the strength of
Divine Toll scales well with additional targets up to 5 since you not only gain more damage from each additional
Judgment, but also gain more Holy Power.
Summon Steward summons an NPC who gives you a
Phial of Serenity, which can be used to heal you and removes most diseases, poisons, curses, and bleed effects. Although there may be situations where being able to remove curses is valuable, Retribution can already remove any diseases and poisons with
Cleanse Toxins and bleed effects with
Blessing of Protection. There's also many tools Ret can use for self-healing, including talents like
Selfless Healer, which makes the healing portion of the ability less impactful as well. Overall it's better than nothing, but Ret stands to gain very little from
Phial of Serenity when most of the utility it provides already exists as options for the spec.
Necrolord
Vanquisher's Hammer is a single target damage ability that empowers your next
Templar's Verdict to also cast a free
Divine Storm. It has a 30 second cooldown and as of a recent change no longer costs any Holy Power. The damage the ability provides isn't particularly good on full AoE when compared to other covenant options, but it's worth noting that it does still perform alright in situations where a primary target needs to be focused down but incidental cleave on other enemies is still valuable.
Righteous Might increases the initial damage dealt and also heals you for the damage done.
Fleshcraft is a channeled ability that creates an absorb shield for up to 20% of your health depending on the duration channeled, or up to 50% if there's a corpse nearby. Due to the fact that Retribution already has a 20% absorb as part of its defensive toolkit in
Shield of Vengeance, that doesn't also require a 4 second channel to use, this ability is unlikely to be very impactful for most content although there could be niche situations it has an impact. In most circumstances though, it doesn't compare very favorably to the other covenant's signature abilities.