#5 Deep Fried Daeva
Same as above, except with lava. And everything is better with lava, right? Lava does damage at an even quicker rate than drowning and they don't have to be submerged, so it's easier to get the foe to take damage. Particularly in the Abyss where lava isn't too hard to find. Plop them down in some molten rock, trap them there, and pull out a marshmallow and roast it over your burning foe.
#4 Dive Bombing
No, not you zooming from above to deliver a killing blow, this is you making a flying foe do a dive bomb into the ground from high above and without a good landing. Sometimes, a player will flee to the skies, sometimes very high, to escape. Your first reaction may be to prevent them from flying up there to get away. Don't. Instead, follow them and chase them up and up. Then use an ability to knock them out of the air! They'll plummet to their death and you can gracefully touch down next to their corpse unscathed. Alternatively, you can lure someone chasing you into the sky and then kill them this way too! It works both ways, so be sure to watch out for someone doing this to you when you were going to do it to them! My first PvP kill (and encounter, for that matter) in this game was this exact method. Certainly was a great way to be introduced to PvP.
#3 IT'S A TRAP!
Causing chaos and discord among enemy ranks is quite fun. What better way to do it than to pour some onto a group of confident players who think they're perfectly safe? Ambush them! There are plenty of ways to set up an ambush, but what better way than to lure foes into it? Just get a volunteer to place themselves in the open. When the local gank squad comes running, have them run toward your ambush point. Then, at the right moment, attack! Bonus points if you can attack that group from multiple directions, or even surround them! It's a shame you can't understand the other faction, since I suspect their reactions would be priceless!
# 2 THE TRAP IS A TRAP!
Spotted an enemy ambush lying in wait? No, don't get a group and go attack them before they spring, that'd be too obvious and they're watching for it. Instead, lie in wait for them and let them work their trap. Once they spring, have your group spring out and attack them moments later! They won't be expecting it and will have no idea where the extra enemies came from. Very tricky to pull off, but it's hilarious and, again, a shame you can't understand opposing factions. Though, just be on guard for the really rare and savvy foes that might be setting up an ambush for your ambush that's going to ambush that ambush. Of course, you could... no, never mind, this is getting too complicated!
When you attack an opponent without a weapon, you'll punch or claw at them, depending on whether you're an Eylos or Asmodian. Beating another player with just your bare hands is perhaps one of the ultimate accomplishments, ultimate insults, or ultimate embarrassments, depending on your view point. Doing this against a fully equipped and skill using foe borders on impossible, but it could be pulled off. And if you completely strip down to your underwear and do it, then you deserve a Crowning Moment of Awesome. Of course, I'm assuming similar leveled characters. A level 50 punching out a level 1 in a duel won't be anything to write home about.
I'm sure there's plenty of other ways to kill your opponents unexpectedly. The environment is always handy and I'm sure there's other tricks abound. If you come up with something that's fun to pull and will give you great stories to talk about, give it a shot! However, always be on your guard. Because you'll never know if that other guy is planning on doing it to you.