I'm comfortable with Gato, Kim, and Iori. Well, Iori is piss-easy so...
It's good that you're comfortable with Gato, dude got crazy mix-ups and a brick wall defense. Iori isn't trash but he's not all that great either, he's a little slow and the lack of his Maiden Masher follow-up hurts him but since it's (more or less) been turned into a DM it makes for a good reversal at times.
I use (L) Kim (with Kyo/Ash assist) and he's a beast, although you have to be really fast with his rekka links because they're a bit easier to punish now compared to his 2002 counter-part but in most cases if you take out one of their people you can hh.A (cross-up)/j.C~cl.C/D(1)~strong rekka (qcb+Cx3) then SC to either (lvl. 1/LDM) Air Hououkyaku.
Combos- cl.C (either hit) and cl.D (1) lead to both rekka chains, if you're in the corner use

+

for extra damage, doesn't work after kick chain though
- cl.C/cl.D(1), qcb+P~uf+K~d+K
- cr.C,

~

+

~

+

- cr.Bx2, cr.A,

~

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- cr.D, (fast)

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(corner only)
- cr.C,

~

+

/

~

/

/

+

/

,

+

if in corner
Hououkyaku/LDM set-ups -

~

is pretty awesome, links to both Hououkyaku
- cl.C/cl.D(1)/cr.C~

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, SC to Hououhitenkyaku (

+

/

) can be used first if you have the meter, after that you can use DM/LDM or tk into it if you want to be fancy
- cl.C/cl.D(1)/cr.C,

+

, SC Hououhitenkyaku (

+

/

) can be used first if you have the meter, after that you can use DM/LDM just like before
- cr.C,

~

+

/

then SC, Hououhiten doesn't work here
- (corner) cl.C/cl.D(1)/cr.C,

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, (SC)

+

/

, (wait until they're at least head level)

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x3 (first hits/second whiffs/third launches), (SC)

+

/

/

Most of these can be done with jump-in C as a starter but in most cases if you attempt a Hououhitenkyaku SC it probably won't connect, and yeah you can switch it up if you got meter by using Hououhitenkyaku then Dream Canceling it to Kuuchuu Hououkyaku (LDM version) around the 8th hit, I'll probably add more later.