Valin tricked Ganner Rhysode during NJO with a mind trick as a child. I think thats what you're referring to.
I'm pretty sure they were all praticing TK on some rocks or something, but Corran can't use TK so he just tricked everyone into believing that they saw him move everything around. I think he didn't even do it on purpose.
__________________ "You must begin by gaining power over yourself; then another; then a group, an order, a world, a species, a group of species... finally, the galaxy itself."
- Darth Plagueis
"She may be small but she packs a punch and when shes in this mood...she goes for my danglers" - Oghren, Dragon Age
It was a joke, or me being sarcastic whichever way you want to look at it.
__________________ Every time this fool be come along
He gots you noobs cryin' out fo' mom
Leave the scene lookin' like Vietnam
Might as well call him "Matt Atom Bomb"
Like his name suggests, he's quite atomic
And this fool - he likes DC Comics
Two energy swords make up his symbol
And trust me, dawg, this homie's nimble
From reading Seba's fight in DN she is extremely bad ass. In the fight she gets some of her skull cut open and she is fighting a bunch of gorog not just welk and even though she is wounded badly and forces welk to retreat she continued to hunt him down.