Clerics...what can we do? :O

Fighting clerics is very gear dependent, the morai combo (absorb heals + mark of weakness while you are slept/sog) is disgustingly good, especially when the target is not fully maxed.

If the cleric is able to kill you without ever waking you up (if mark of weakness does like 1/3 of your hp).. you are going to be fighting a VERY difficult uphill battle. Really your only option in that case is to try to resist the control skills. Most clerics I've fought start with sog, and just before it ends try to sleep you.. so you can break that combo with adrenaline surge near the end of sog. A good cleric will likely see this and not blow their sleep while you are immune to it, so you need to use those few safe seconds doing something (you'll likely get slept as soon as adrenaline surge wears off). If you can, try to go for the kill with some kind of spark combo (or sleep MS) or reversion + ice prison, and if that is not possible, at the very least heal yourself to remove the absorb heals and fill your hp bar. I've had limited success with this, but most eps I've come across are fairly predictable, you can try to single spark resist sog (I'm able to successfully resist it maybe 50/50.. probably at least worth a shot).

If they do have to wake you up (like in my case), you have a few more options. Mark of weakness usually hits me like 1/5 to 1/6 of my max hp (from end game eps), and in a very long sog + sleep combo they will still never be able to get me much further than half hp (thankfully mark of weakness has a 10 second cd). They usually have to wake me up when I'm about half hp after a charm tick, so it is very easy to just hit a pdef charm, elemental shell and morning dew (fow usually doesn't work because they can easily will surge as they wake you up). If they triple spark before waking me up, probably a good time to immune or possibly just sleep + blink away if you don't think they are expecting it.

Killing the ep shouldn't be terribly difficult, it just takes time (need a crit with a spark combo usually.. and you just need to wait for an opportunity to attack). The real trick is staying alive long enough to kill them.. and that is largely gear. You could also try heart of steel on genie, that could really come in handy. You kinda have to think of this ep combo as similar to the problem we used to have with nixes.. it really just comes down to gear. If you weren't able to tank bleed, life sucked.. but after gearing up a bit you were able to deal with it easily. The nix damage was essentially static, just like mark of weakness. Being one of those odd skills that ignores damage reduction (like wind shield/aquaflame armor etc), it also ignores amps (dragons/extreme poison etc).. which means it is extremely good at killing people that need damage reduction to stay alive, and not quite as scary to people that don't die to non-amped hits.

I wish I had something more to tell you, but unfortunately there aren't many options

Adrenaline Surge, Will Surge, and Faith are the three genie skills that will prove most useful in resisting the combo. Adrenaline Surge to avoid sleep. Use Will Surge when you see them casting SoG and it will immune you to the seal. Faith has two uses: A. much like using Will Surge to block the seal from SoG, except you can use it to avoid SoG altogether, though note that it will not break you out of SoG since it is unpurifiable and B. to faith out of or resist sleep. Heart of Steel will also probably prove useful.