A.N. Part of this chapter was inspired by the episode Baby's First Word.
As the years went on, Gargamel had worse luck than ever in catching Smurfs. Oh sure, he had a chance as long as they traveled outside the protection spell, but it was a slim one because they always remembered where the edge lay - just outside the Smurfberry patches - while Gargamel kept forgetting and kept crashing onto the edge. Azrael and Scruple were smarter than Gargamel about the edge of the protection spell, but only Scruple gave up catching the Smurfs entirely. The fact that he was never really into catching Smurfs at all helped with that too. As the years grew into decades, even Gargamel had to give up and concentrate on other matters like practicing spells. This resulted in him unintentionally making his magic stronger.
As for the wartmongers, since they never saw the pixies again and only rarely saw the Smurfs when Greedy needed to get ingredients for his swamp root stew, they soon gave up too. In fact, none of the other species in the swamp worked as slaves so the wartmongers ended up having to do all the chores themselves. This, combined with Boggy telling his future children about his friendship with the Smurfs, gradually led to the wartmongers becoming nicer (for them anyway) and less lazy.
Decades grew into centuries. Baby Smurf became Magic Smurf, as he gained more magical powers than even Papa Smurf ever had. Magic Smurf also became the protector of the forest, and with his magic was able to vanquish Gargamel for good. This was the result of Gargamel about to take over the world by killing off the forests (except for a patch around his hovel since he needed plants and such for potions) and overpowering various rulers. Magic Smurf used his most powerful magic that not only gave the animals stronger versions of their skills, but also enabled the Smurfs with weapons that were invincible. Actually, in the animals's case it was really cool. Deer had their antlers replaced with swords or lances, rabbits were able to hop even higher than a kangaroo could, beavers were able to chew through stone and metal, and birds could fly so fast that they almost became invisible. Eventually all of Gargamel's conjured warriors and defenses were destroyed, and the outcome of the battle depended on whether Magic Smurf could defeat Gargamel or not. Obviously he did, and he not only destroyed Gargamel's magic entirely but also caused Gargamel to disappear forever. Azrael, being a wizard/warlock's cat and so was able to live a long time, also disappeared. Scruple, who didn't depend on Gargamel for existence, was the only one left. Due to fear, Scruple promised to reform if Magic Smurf didn't cause him to disappear. Magic Smurf agreed on the condition that Scruple first earned himself a living without magic, so that he could discover the value of hard work. Scruple did by working in a restaurant, first being a busboy, then a waiter, and gradually a cook. This caused his ability with potions to increase, also causing him to be very grateful for Magic Smurf's leniency (when he first started working he was resentful). He ended up reforming not only on the outside, but also on the inside, and later concentrated on creating healing potions and the like for the benefits of others.
Baby Smurfmaid and Baby Smurfpixie had wondrous futures too. Baby Smurfmaid became Aquatic Smurfette, as she gained the ability to talk to aquatic creatures and was even able to control water. Baby Smurfpixie became Aeronautic Smurfette, as she could not only fly but also build flying machines that worked better than Handy's wooden airplane ever did. She also gained the ability to talk to flying creatures.
In short, the Smurfs, apart from that last battle with Gargamel, had a peaceful, happy life for the rest of eternity.