Umbreon

What this Eeveelution lacks in strength is compensated by sheer bulk. It sports oustanding survivability, and can help hold down a gym very well (assuming it doesn't meet Machamp). However, gym defense is basically its only real niche in the PvE meta, as it genuinely shouldn't be used as an attacker.

Best PvE Offensive Moveset

• Snarl is superior to Feint Attack, holding a slight numbers advantage in every aspect.

• Foul Play is superior to Dark Pulse; despite both moves being 2 bar, the former has a significantly shorter cooldown and as a result, higher DPS.

• Last Resort and Psychic have little to no offensive viability.

Best PvE Defensive Moveset

• Snarl is slightly superior to Feint Attack, dealing higher defensive DPS.

• Psychic is the best Charge Move for defense due to its coverage against common Fighting-type attackers. 

• Dark Pulse is marginally superior to Foul Play, sporting a slightly earlier damage window.

• Last Resort hits Umbreon's counters for neutral instead of resisted damage, but it's also much easier to dodge.

Snarl is recommended over Feint Attack for its very fast energy generation, though the latter does offer more damage output. 

Foul Play is usually the preferred move, due to its lesser energy cost, but Dark Pulse does provide some extra power for one or two more fast moves needed to charge it. Umbreon's lack of coverage moves is its liability, so while Community Day-exclusive Last Resort does cost more energy to use and is Super Effective against nothing, it's a must to deal neutral damage if the opponent would resist Dark-type moves. Psychic is an alternative coverage option added during the 2nd Eevee Community Day, and is preferable to retaliate against Fighting-type Pokemon, but risks Umbreon being completely resisted by other Dark-type Pokemon. 

Running both Foul Play AND Dark Pulse is also a valid option, giving Umbreon flexibility in terms of both energy and burst, and Dark is a fantastic typing to go monotype due to its relative lack of double resistances. However, this leaves Umbreon without any form of coverage.