Try delaying the j.D a little bit, you want to the follow up 5C to hit at about Tager's head height so they will be low enough for the 236A to connect after 6C.
As for Terra Break, you need to time it so they land right on the attack at its high point, and not dead center.
The default solution to number 20 is OD>6C>SB(623)>j.C>j.D>step forward slightly>5C>236A>5B>5C>6A>SB>6A>3C>AC(whiff)>5C>5D>AC>SB>MTW>TB>6B>6B>SB
This one was posted by Snatcher in the gameplay thread.
OD, 6C xx spark, 5C, 6C, jC, jD, 5C, 6C xx spark, 5B, 5C, 6A, 2C xx collider, 5D xx spark, gadget, rapid, gadget, rapid, spark
And here is a video of one https://www.youtube.com/watch?v=clFsjt0FD7E
Pick your poison.