This is simply an excellent presentation by Harapan Ong.
Before you learn how to cut to specific cards, you will learn an easy to do, false, up-the-ladder cut technique that forms the basis for the presentation. The up-the-ladder cut, outside of this effect, stands out alone--it is really quite deceptive and more elegant than your standard up the ladder.
You will the learn how to utilize this move to produce an increasingly impossible number of packets with corresponding cards on top. First a single packet with an ace on top. Then two packets both with twos on top. Then 3 packets with threes and 4 packets with 4s. You then blow it out of the water by impossibly producing 10 packets with cards one through 10 of the same suit on top.
The premise of building in the false cut as the basis of this effect is genius, as the cards look more and more shuffled with every step, making each subsequent cutting sequence seem even more impossible.
Harapin Ong is an expert teacher. The teaching is just the right speed and he even gives you mnemonics to help you with the final card set up. Ong carefully teaches each component thoroughly but still maintains an excellent pace. There is even an annotated, slow motion presentation at the end to sock things in.
The presentation is whimisical and clever. Sure, it's a bit of showboating, but it's a nice bit of eye candy to perk up your audience.
The moves themselves are not difficult once the cards are set up, but it will take practice to learn the steps in order, get up to speed, and make it look as smooth and casual as Harapin Ong makes it seem.
On the downside, the moves are taught assuming a preset deck. As it involves setting up 20 cards in advance, it might be difficult to do on the fly. Not impossible in front of an audience, maybe, but not something, for most, that would be easy to do undetectibly.
Nevertheless, this effect really shines. Because it is so flashy, it would make a great opener, which would allow for the deck to be set up well in advance.