"Invincible" is a massive book with about 120 games. 80 are full commentaries with detailed analysis. The games here are magnificent struggles with large scale fighting being the norm. However Shusaku demonstrates his mastery of the positional features of the game and in every game he demonstrates his superb positional judgment.
The book contains thousands of lessons and is a great way to see the 3-4 point in action. These games are timeless and playing through them is like listening to great classical music or seeing a great artist in action before your very eyes. Invincible's lessons are supplemented by the history it presents along with every game and with a well-written introductory chapter (about 25 pages) documenting the history leading up to and including Shusaku's career.
If you love great games you will love this book. This book is well suited to anyone who is able to learn from professional games, although weaker players may find this book a struggle. Invincible is great at teaching through exciting struggles but its real strength is teaching and fostering a love for go and its culture.