I found a few other ways that Squigly can use an assist to get a charge mid combo, in addition to the one using Dive of Horus assist that I posted above. I feel like this is pretty relevant to people trying to make Squigly teams so I wanted to share what I found.
Worth noting: if you move forward or backwards while in stance, you start building undizzy, even if you're in the first chain. Most of these conversions need to do that so it's worth mentioning.
c.LK c.MK s.HK + call Updo xx stance, walk forward, OTG c.LKx2 s.HK etc
-needs OTG
-requires you to walk forward in stance so you build undizzy earlier as described above
c.LK c.MK s.HK + call Napalm Pillar xx stance, walk forward, OTG c.LKx2 s.HK etc
-needs OTG
-requires you to walk forward in stance
c.LK c.MK s.HPx2 + call Platonic Drillationship xx stance, walk forward, s.LP s.HK etc
-saves OTG
-easier to hit confirm
-requires you to walk forward in stance
-scales pretty bad cause the assist has so many hits
c.LK c.MK s.HPx2 + call H Beam xx stance, walk forward, s.LP s.HK etc
-saves OTG
-easier to hit confirm
-requires you to walk forward in stance
-scales pretty bad cause the assist has so many hits
-does not work if it hits a crouching character; if that happens you can combo into Silver Chord to force them to stand up
c.LK c.MK s.HK + call H chair toss xx stance, walk forward, c.MK c.HP xx Silver Chord, etc
-uses OTG
-requires you to walk forward in stance
-scales bad cause of the c.HP xx Silver Chord
-uses up your kick stance
c.LK c.MK s.HPx2 + call L Beat Extend xx stance, s.LP s.HK etc
-saves OTG
-you don't have to walk forward while charging! only one I could find midscreen
That's all I found before I realized "wait I don't play this character why am I putting so much work into this". I'm sure there's others, or more optimized conversions off the ones I found, but hopefully this is useful to people trying to work Squigly into their teams.