Night Fae
Segen der Jahreszeiten is an ability that buffs a friendly target, rotating through the four seasons as you use it:
Segen des Sommers,
Segen des Herbstes,
Segen des Winters, and
Segen des Frühlings. In addition to providing a decent damage buff from
Segen des Sommers, it's an ability with decent utility as it can also be strong to help out a healer if necessary with
Segen des Frühlings.
Segen des Sommers 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,
Zornige Vergeltung, is a 2 minute cooldown. (Even if this period is reduced by
Segen des Herbstes,
Zornige Vergeltung'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
Segen des Sommers does Holy damage it doesn't actually get buffed by Ret's
Meisterschaft: Urteil des Hochlords, 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,
Der lange Sommer, increases the duration of
Segen des Sommers.
Seelengestalt teleports you forward a small distance and increases your movement speed for 12 seconds, but using most abilities will cancel the
Seelengestalt 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
Ascheweihung is a targeted ground effect that does ticking damage to enemies inside over 30 seconds, allows
Hammer des Zorns to be cast while standing in it regardless of the target's health, and buffs
Hammer des Zorns's damage. With
Ascheweihung 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,
Geheiligte Einsicht, increases its ticking damage on the lowest health target.
Schattentor is a 1.5 second cast that teleports you up to 35 yards at a targeted location. Similarly to
Seelengestalt, 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
Göttlicher Glockenschlag is a 1 minute cooldown that casts
Richturteil on up to 5 targets within range. The
Richturteils cast do double their normal damage, the
Richturteil debuff is applied to any enemies hit, and you gain 1 Holy Power for each
Richturteil 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,
Läutende Klarheit, which provides a chance for it to cast its empowered
Richturteil four times on your primary target instead of once. For AoE situations, the strength of
Göttlicher Glockenschlag scales well with additional targets up to 5 since you not only gain more damage from each additional
Richturteil, but also gain more Holy Power.
Provost beschwören summons an NPC who gives you a
Phiole des Gleichmuts, 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
Toxine läutern and bleed effects with
Segen des Schutzes. There's also many tools Ret can use for self-healing, including talents like
Selbstloser Heiler, 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
Phiole des Gleichmuts when most of the utility it provides already exists as options for the spec.
Necrolord
Hammer des Bezwingers is a single target damage ability that empowers your next
Urteil des Templers to also cast a free
Göttlicher Sturm. 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.
Rechtschaffene Macht increases the initial damage dealt and also heals you for the damage done.
Fleischformung 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
Schild der Vergeltung, 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.