My favorite dark type. For a wall, you can use:
Toxic-Walls need this move
Mean look-Traps foe
Payback-Works well with low speed
Protect/curse/wish-protect for further stalling, curse to power payback, or wish to heal Umbreon
or you can make him a passer
Baton pass-passes to partners
wish-is baton passable, and because of umbreon's low speed, they switch in without getting hit
Mean look /Curse/double team -mean look is baton passable, curse if you are willing to give up speed.
I like to use the 1st or the 3rd one.
Confuse ray-Further annoyance
curse-powers up umbreon
Trump card/Faint attack/Payback-Trump card has incredible amounts of damage after cursing. faint attack has okay power, and has infinite accuracy. there's also the move payback, but I suggested the others because confusion may keep your opponent from hitting you, meaning you don't get double power.