(Holy shit this turned into a wall of text)
Yeah, I waited for a while for someone to invade me while I was killing enemies in the Undead Settlement. He wore a weird hat and an Exile Greatsword. I emerged from the house near the beginning with the fire pit and the 20 million Workers idling just outside, and used Jump For Joy to call him over to me. I could have thrown lightning bolts at him, but I didn't care. I was ready to have fun and have my first real fight.
He walked over to me, becoming more cautious as he got closer. I jumped at him and swung at him with my axe, causing him to dodge away. While I remained in place, he swung wildly at me wielding his two-hander one-handed like a retard. I backstepped away, and then stepped back in and smacked him with my axe. I continued pursuing him, attempting to hit him, usually succeeding as he made no effort to exploit his clearly superior reach, and never using his spinning attack or the super armor which I'm assuming his greatsword probably gave him. I ended up winning without taking damage.
The next fight was even worse due to the fact that it was basically the exact opposite. I was in the swamp, engaged in mortal combat with a giant enemy crab, attempting to find his weakpoint. I was invaded by a dark spirit, but I was determined to kill the GEC first so it wouldn't kill me while I was fighting the guy. Just as it was about to run out of health, a huge rain of magic pelted me from offscreen, killing me while I was at almost full health.
I used an ember. The same guy invaded almost immediately. This time, I sprawled out on the ground and waited for him to come to me. I was essentially holding my hands in the air, trusting him to find me and challenge me to an honest fight. Naturally, he did find me, although he didn't so much as hesitate to rush me and attempt to kill me as I lay on the ground defenseless. I was luckily able to roll out of the way just in time. He was weilding what looked like a mini-scythe in one hand, and a staff in the other which he immediately used to spam soul darts. I dodged them and hit him with my axe (truly a groundbreaking tactic, I know) hoping to stunlock him and hold him still. My strikes did pathetic damage. Just after my third hit or so, he seemed to magically become un-stunned, and instantly prepared an attack with his mini-pick-thing which met my face sooner than my axe had moved an inch from where it was before. It did nearly a third of my health. And then he hit me again. And again. And again. And I died.
This happened a good 10 more times over the next 10 minutes or so. I then decided to leave the area, and come back over an hour later. He immediately invaded me again. I couldn't win. His weird weapon somehow was able to damage me many times more than my lightning imbued axe (which has an attack power of over 400 and is a one-hander) he had so much more health than me that no amount of damage I ever did to him was significant (My health is already like 1000) and so much magic that he could endlessly spam sorceries as soon as I walked more than 3 feet away from him. I gave up, extending a goodbye to him by extending my middle finger.
Later, as I was in front of the area of the Abyss Watchers, I decided to invade someone again since I got several red eyes from those stupid knights who drop them. Lo and behold, there was the same exact guy, acting as a white phantom for the host of my victim. And he was facing away from me. I decided to give him a taste of his own medicine, running behind him for surprise buttsecks while he was in the middle of fighting. My riposte drained his health by about a quarter.
As he stood up, his health just fucking came back. He didn't even use estus, it just rose back up as if he was wolverine. I backstepped away from his attack, and then furiously wailed on him to the same result. Panicked, I dodged away from him, accidentally becoming stuck between a tree, a wall, and the host herself. Determined to take advantage of my horrible misfortune, they both descended on me as I rolled in place.
And then all was still.
Dark Souls 3
Maybe I should do a normal run in online mode instead of waiting until NG+ to play online. I don't know if that would actually help, though, since I have no clue how the matchmaking works.