Oh boy, you know that if the other "longest one" keeps going we will never get past it, right? And let me tell you those guys aren't even close to letting up on that RP.
That aside, I think we should incorporate every topic and tag available into this RP. Take a hint from the other one and do a multiple worlds kinda RP where our characters are summoned from different worlds to do a battle royal. Use one of those PVP arena battle systems. From there, after one emerges victorious they go together or on their own ways in another journey maybe in another world side from their own.

On certain dates(real life) you should organize events to increase the immersion, like in Halloween, make it that some boss comes down and everyone has to join together and attack and the creature drops some special loot. Make it at least one week long since not everyone wants to spend the festivities typing on their comp.

Always leave it open as in "Apply".

And finally, you should incorporate smut.