Krillin's Ki Blasts arc upwards until they exit the screen vertically.
After a little while, they come falling back straight down. The button strength determines the distance it falls back down.
The EX version fires a larger, twice-hitting energy ball. That too has three different versions which fall back down on different distances.
(pressing QCF+ either LP+MP, LP+SP or MP+SP). This EX version can't be chained like the regular version can though, but you can link into it.
You can even link into it after 3 consecutive Tricky Blasts, as a fourth blast. This rekka version fires straight rather then in a curve.
LP+MP fires it straight but slow LP+SP fires it straight but fast and MP+SP makes it go just a bit diagonally up while going forward.
Also has a Fake version by pressing QCF+Start.