"You ran raids with the resistance in Ba Sing Se, didn't you? My name is Erok, I used to supply information to your friends a few years ago. During that time, I saw you when that wound was more fresh," Erok gestured to her eyepatch, "I didn't expect you of all people to come looking for me. And you're right, it has a lot to do with Lotus."
Erok turned away briefly, scanning the horizon quickly.
"And while I'd like to get to the Ember isles myself, I need to wait for a message. Once it arrives, we can leave. Otherwise--"
Erok cut himself short just as a messenger hawk swooped down and landed on a low branch next to him. Quickly unfurling the scroll from the hawk's pouch, Erok gave the hawk some bread as a signal to return home. While the hawk took off without a sound, his face became grim and pale as he read the hastily written note.
"What timing. This is it. Mao, if you are ready now, I can take you. I am needed at the isles to protect the Avatar. On the way, you can explain yourself more fully."
Erok turned and swifly hopped down the bank onto the sandy beach, to the water. There, he moved his arms in fluid motions until a small boat made entirely of ice had materialized. Erok turned to Mao expectantly.
"More than you know. Aren't you a little far from home?"
The nearest village had to have been at least thirty miles away; it was too dangerous these days for people to live on their own without the protection of walls, especially so close to the sea. Erok turned to face her, wondering why she had approached him so openly with small talk. Perhaps she had some idea of who he was, or what he was doing. Attempting to size her up and evaluate if she would be a threat to him, Erok tried a more direct route.
I don't mind @pyroman's suggestion here; a surprise meeting would certainly be acceptable, but there has to be some sort of pretext to why Mao would seek Erok out. For example, perhaps she had heard from the same merchants that Erok had dealt with that there was someone searching for the Avatar who had suddenly left town in a hurry. Mao could deduce that Erok might know enough information to be helpful in her own search for the Avatar.
At the same time, Mao doesn't know exactly who Erok is, nor does she know his intentions; Erok doesn't know Mao either. Obviously how she handles the situation is up to you. I was planning on having Erok wait for Chit to get back to him via Hawk, and if @Shanks took too long to make a post, I'd have Erok begin to worry that something had happened to him, the Avatar or both, and take off for the Fire Kingdom after some delay.
As a side note, I'm actually currently re-watching the original series. It's aged pretty well. Not sure if I'm going to re-watch Korra just yet though, seeing as I just finished it when the series ended.
Meanwhile, at the coast of the Earth Kingdom's Westernmost peninsula, Erok was waiting.
An uneasy chill may have permeated the air and earth, and the tree he leaned against as he took a break from his day long march had become withered from the unnatural winter, but Erok took no notice of these things. Instead his eyes scanned the horizon out to sea, where he knew the Fire Nation lay in wait, to the Ember isles, where the worlds saviour trained. Looking further, to the northwest, he knew that the Water Nation was going to make an attempt at the Avatar. He knew all this through his various sources in the Earth Kingdom. Traders and Merchants who spread rumors, but truth as well.
Erok had sent warning to his only remaining Fire Nation contact, Chit Zai. If Erok knew what was happening, then Iluq would know as well.
Erok had only to wait from the all clear from Chit, then he could make his move. He didn't like the idea of being recognized as a Water bender in the Fire Nation without someone to vouch for him.
Appearance: Standing just over six feet tall, Erok has a medium to thick overall build, dark skin as typical of Water tribesmen, and short brown hair, slightly longer on the left side. He wears neutral colored clothes and overcoat when traveling, but also wears a black and blue armored suit, complete with an insulated mask while on a mission.
Element: Water
Abilities: Erok is a soldier trained in combative water bending, as well as being trained in both hand to hand combat and with various swords. His training has increased his endurance, mental and physical stamina, in addition to active duty giving him experience in battling benders of other elements.
Erok is nearing mastery of water bending, and in particular, his greatest asset is his creativity. Work as an assassin and spy have lead him to be proficient at dealing with small groups of opponents; facing off against more than four opponents at once while alone places Erok at a disadvantage. However, Erok can often make a quick escape if he is alone. Erok is capable of freezing and boiling water without much effort, and his water movements are unlike other trained water benders in that his water will travel more often in specific shapes, rather than just waves. All this considered, Erok cannot control massive amounts of water at once very easily, instead putting a heavy focus on smaller amounts that he can exert better control of, in order to compensate.
Ice Grenade: Erok creates a hollow sphere of ice with liquid water inside, the liquid is then superheated before propelling it towards a target. The resulting explosion is not truly concussive as the name 'grenade' suggests, but it can have the potential to affect multiple human targets at once. The area taken up by the explosion is left too hot for a regularly clothed human, especially those in heavy armor, to be in, as doing so can result in major steam burns. The shrapnel created by the shattering ice is traveling fast enough to crush or pierce lightly armored targets. Unfortunately, this technique is rather difficult to preform on a large scale without either cover from a surface or from others defending Erok while he makes the grenade. In addition, the grenade can be made in various sizes to accommodate different needs. Quick escapes can be made from multiple enemies under the cover of such a grenade if it were the size of a fist, which is faster to create than one which would fit a fully grown human inside. Power scales accordingly, but almost always leaves strongly built or natural surrounding structures intact.
Ice Spike: This is not usually useful as a combat technique, but is instead a technique used for assassination. By bending water into a thin spike and making it much colder than average ice, it can easily pierce flesh, even though heavy clothing. This technique relies on absolute perfect accuracy, so hitting the proper area of a moving target in the midst of battle isn't usually an option. Using a variation of this technique, Erok can bend a spike large enough to be used as a spear, staff, or other such blunt force weapon. With more concentration, Erok can also make a dagger capable of cutting.
Steam Screen: Another technique originally not meant for combat, Steam Screen differs from the smaller Ice Spike in that it can be used to completely disable opponents in short order, so long as they are not aware or unable to defend against it. Typically, Erok will rapidly heat water from below his enemies until it boils, propelling steam upwards, potentially blinding foes. The scale of usefulness therefore depends almost entirely on how aware the foe is of their surroundings. If they are aware of the water surrounding them, they are not as likely to be taken unawares and harmed by it. Variations of the steam screen include shooting plumes of steam towards an opponent, creating a 'fog' through which Erok can conceal his position, and in certain situations, be useful as a propellent.
Survival Skills: Through experience he has also gained considerable survival abilitieswhich aid him when away from civilization.
Personality:
Erok is a straightforward man who prefers words to fists when possible. Usually cool-headed, Erok tends to become rather detached under pressure, a coping mechanism meant to shield Erok from emotion while working as an assassin. He is both an excellent tactician and strategist, although this is rather limited to his own abilities, as he tries to not count on the success of others in order to avoid disappointment or loss. Therefore, while he can construct an excellent large scale strategy, he is better served on the battlefield.
Erok was born in the Northern Water tribe to a high ranking soldier in the Water navy. An average childhood was enjoyed briefly before Erok's father, Koahn, was injured at sea. Having returned home safely, Koan nonetheless suspected war was fast approaching, and so began his son's water bending training, with the hopes that Erok would join the military in his stead. Erok agreed. The lessons were hard, but well learned, as Erok's skill grew. Eventually there came a point where Erok realized his control was greater than his overall power. To compensate, Erok grew creatively, bending water into intricate shapes and forms, eventually becoming one of the fastest water benders in the North.
Many years passed, and the Northern Water tribe had been annexed by the Southern Water tribe, now collectively known without prefix. Erok continued to serve in the military in his father's stead, and rose through the ranks until his talents were noticed by his superiors, who promoted him rapidly through the ranks of the intercontinental forces, until he was given the chance to form his own assassin group.
As Erok completed mission after mission, his patriotism began to severely waver. He could understand the political assassinations and military reconissance; he had been told that the other nations wanted to crush the water tribe entirely. However, he found this to be entirely untrue, that the other nations were actually defending themselves from a war Iluq of the Water Tribe started. Filled with regret and uncertainty, Erok made an uneasy contact with a Fire Nation Lieutenant, Chit Zai, through which Erok gave information about the Water Tribes movements, in order to defy Iluq from behind the scenes, effectively halting the Water Tribes advance on Fire territory. This unfortunately lead to suspicion, and a Fire Nation traitor operating as a spy for Iluq's forces burnt down the building in which Erok was hiding a dead drop meant for Chit. All believed Erok to have been killed in the blaze at the time, as a charred corpse with his coded credentials was found, but Erok managed to escape alive, using water bending to keep the flames at bay.
Erok made it his life's mission to dethrone Iluq after his apparent death, but couldn't find the right opportunity to do so; Erok's face being known by the Water Tribe, he wouldn't have been able to set foot in Water territory. So, by biding his time and gaining information, Erok found his intelligence recon skills put to good use as an information broker. During this time, he learns that the Avatar is still alive, and that the Avatar would be able to put an end to Iluq, in order to return balance to the world.