I have also started playing KI so I'm learning as I go, from what I have been watching your Glacius looks good. Here's some things I noticed, I'll keep updating as I watch the videos.
Against Sadira, I always like to have a Hail projectile out, this makes it so she can't approach through the air
I like your use of c.HP, but be careful as it becomes a high at farther ranges
At 4:25 of the second video you took your opponents first life and used meter when you didn't have to. In that situation I would have extended the combo so that I could end in the battery ender, and if I have full meter I would just drop the combo immediately so my opponent doesn't gain Instinct/Meter
You should anti-air more, his back.HP, c.HP, and Puddle Punches are good AAs. His jump back HK is great as well (this is the only reliable AA I've found against Sadira/Thunder), but you push yourself into the corner. And you can't cancel into Hail like you can back.HP and c.HP, or shoulder to reverse positions.
Against Orchid, when I get really scared of her slide. I'll just always hold a LP Hail so that if she tries to Slide, even if it hits, the Hail will hit and you get a full combo with c.LP. This also works for Sabrewulf with his Run mixups, if you have a Hail all you have to do his block his slide, and if he tries the overhead the Hail hits him.
@8:15 of first video. Very good shadow counter! I think that being able to utilize this will help Glacius against characters like Jago/Sabrewulf. Against Jago, you can punish that double step kick (forward.HK) if you do it between the kicks. Also if you Shadow Counter his laser sword move (the first sword slash), even if he does the HP version which has two hits, your Shadow Counter will still beat it.
@19:30 of first video. Glacius back grab is +13, while his forward grab is +15. So doing a shadow Ice Shatter only combos on forward grab.
You probably already know this too, but you should do an Ultra as soon as you can, as it will end the game before they have a chance to break.