Thanks for the advice!
Some more questions: How important is it to have a buff or debuff-like skill on each character? Is it worth keeping the attacks that debuff enemies even if they're weaker than straight up attacks (a la Fang Breaker)?
I'm just finding it really hard to get everything I need when every character is limited to only 6 slots (Some have started to earn a 7th slot but along with that comes new important sounding skills like Concentration/Charge). :-/
It really depends on your play style.
Generally, if you end up never using the skill, it's a wasted slot.
You can get most trash mobs in the dungeons down with sessions, so when you add skills ask yourself if that's what you are going to apply in boss fights.
I also skilled Charge because I thought it sounds interesting, but I ended up NEVER using it so far. It feels like a wasted turn, that is better spent preparing to either getting hit directly afterwards or trying to take down an enemy to avoid that hit that will come next.
On the other hand, debuffs are much more useful to me personally - Charge will make your own attack hit harder some time in the future, while debuffs can make everyone's attack hit harder with the next person up in the turn order already.
I found the ones that increase your own offense and decreases enemies defense to work best for my play style, but the opposite can work for you (decrease enemies offense, increase own defense).
I spread out a few of those debuff skills around each character, which gives me the chance to do something with them even if none of their skills will hit a weakness for a session, and changing is not an option for some reason - so they can use their turn using a buff/debuff.
Don't worry too much about most of the debuffs by the way, you can buy or find items that do the same thing essentially, and carry them with you as some kind of backup skill!
EDIT: Oh, I re-read your question, you are asking specifically about stuff that is a light attack but can cause stun etc? They are really usefull! If it starts a session anyway, the bit of extra damage is neglectable over the massive advantage a successful stun or debuff can give you. And if it's not starting a session, you are basically applying a debuff with some extra damage. You should really consider them over heavy attacks, if you can't get rid of anything else.
My Itsuki was a Great Lord for the whole game, but I managed to get a Wyrmslayer weapon (and a Wyrmicide as well, IIRC) somehow. Forget which one it was though.
Yeah, had that one too, has to be one of the earlier weapons (in the dungeon where Ellie joins), and it felt superflous, so it got kicked.
I'll see what I can do in the final boss fight without it. :/