Out of all the new experiences being away from the desert brought, the one thing that Tié didn't expect was just how acute his seismic sensing had become, usually he could simply use it to sense where bendable sand was and more experienced sand benders could use it to sense where dangerous sand pits, buried monsters/treasure and sinkholes were.
That however was the extent of the sandbender seismic sense use, the grainy sand simply not being solid enough to convey more complex messages, the more he started walking on solid rock and ground however the more his senses expanded in ways he'd never expected before.
It wasn't large earthquakes that surprised him a lot, after all everyone could feel those and they were quite common in the earth kingdom, no it was the smaller almost constant vibrations that shocked him.
Everything seemed to shock the earth at least a tiny bit, he could sense the carts impacting the ground as they rode along, the beasts of burden gripping the ground and kicking off and a myriad of other things that he didn't have a clue what they were, as he could sense the vibrations within his range but the sources were outside of it.
Naturally being the curious child and bender, he was he decided to experiment with his newfound senses, blindfolding himself and then walking through a maze, jumping in between different compositions of rock, to randomly taking of his sandals and counting how many worms and other subterranean creatures he could spot.
He kept up experimenting randomly throughout his journey and stay in the fire nation and that meant that Progress was slow and erratic at best but it was without a doubt a cool trick.
It was however sometime after teaching himself how to slide through the earth with earthbending, that he realised the combat potential that seismic sense had when combined with underground movement, as unless he was fighting against another earthbender, he could sense his opponent whilst they couldn't sense him allowing him to attack from relative safety and recuperate.
Still, without a proper earthbending teacher this would doubtlessly be difficult to train and as such he decided he needed to practice on a live target, what spawned from this was a prank run on Hue-Sar that would go a little something like this.
Tié would ambush Hue-sar during Hue-Sar's daily routine when he walked through a particularly badly maintained alleyway, Tié would proceed to hide underground and then send small unnoticeable increases in the ground where Hue-Sar was walking causing the spirit turned mortal(?) to trip. tié even purposefully tripped him around the same places every time Hue-sar walked their to help with the ruse, when Hue-Sar usually fell to the ground he would then usually proceed to loudly start ranting about the shoddy human pavement design.
This may or may not have been effective training, certainly was morally dubious, but it was doubtlessly rather entertaining, especially when Hue-Sar went to the alleyway one day with a strange measuring device, a crowbar and a tiling hammer before repaving and flattening the entire section...which resulted in him getting arrested for altering and damaging public property.
It was at this point that Tié decided it was far enough as any more would be cruel and undeserved, well that and believed he'd sufficiently gotten payback for the sandwich crisis in the desert, especially after Hue-Sar ended up getting sentenced to thirty hours of community service...somewhat ironically spent repaving the local roads.