Hello! This is the bio of how I portray Lalna in my RPs.
Lalna is a scientist who lives far out from the spawn point of the world, near the "inconspicuous f**king hill" warp zone. (Lal didn't name it that, Notch did. long story.) Now I use a LOT of headcanons for Lalna, but I'll get to those in a minute. In the Yosummer universe, Lalna and Sjin used to date until an incident called "The Reset." (That is also a long story.) The Reset made Sjin forget all about their relationship, and Lalna had written a book and given it to him as him a reminder. Even after reading it, Sjin couldn't recall having any feelings with him, so they broke up.
This is where the headcanons come in.
Lalna's feelings of loneliness caused a chip in his brain, placed by Xephos years ago in Yoglabs as an experiment, to malfunction and turn on. This unleashed his alternate ego, Livid. As Livid, he is able to, and WANTS to experiment on anything he can get his hands on. Livid is a murderous sociopath, who Lalna has little control over. Currently IC, the remote that Xeph-Bot built to turn off the chip was destroyed in lava while Livid was switched on. You can tell when Livid is switched on by how Lalna talks and moves. When off, he talks normal and shows no twitching. When on, he sort of glitches like a robot, and twitches sometimes.
Lalna is very scared of Lalnable, and will always have a weapon when he's around. He tries not to show his fear, but everyone knows he's scared.
Lalna still has feelings for Sjin but does his best not to show him for fear of scaring him off and losing the chance to even continue being friends with him.
That's it really. :3