I only solo play and I don't do mods. At first I did find Mistlands hard to play through and died countless of times but i enjoy the mist because it gives you a challenge but now I walk through with ease, all you need to do is learn how travel the terrain and in the Mistlands higher the altitude you are the better! Only ever had the one seed which is still far from explored and I have more than 2000 in game days played. Before the Mistlands update I had travelled in that biome and after the update those areas didn't have the mist but Seekers still spawn, so I used that as training ground to learn to fight the Seekers without having disadvantage of mist.