After the great rescue, the Peaceful Realm, true to its moniker, entered a state of lull, apart from Griar, no one had any reason to even think about stepping into another realm, and even less reasons to willingly get anywhere close to the undead, everyone was simply content on living, having friends to talk to, practising their hobbies, or starting families…
No one held any hope of standing up to the Undead Empire anymore, they had every advantage to do so in the Emerald Realm, and still experienced a crushing defeat, now that their numbers were further lowered, and the undeads, in turn, only grew exponentially stronger, the only logical thing to do was simply enjoy the peace they had been granted, if Death was going to claim them, then it was going to do so when their lifespan naturally exhausted.
