N2+3H2→2NH3

N2+3H2→2NH3 is the final stage in Summer Lesson.

Battleground

 * The stage begins with a St. Pigge the 2nd, followed by three Pigges.
 * After 40 seconds, an Owlbrow spawns, with another one spawning 10~13.3 seconds later.
 * After 100 seconds, Pigge starts spawning in 30~50-second intervals.
 * When the enemy base is attacked, Doge Dark, Teacher A., Shadow Boxer K and Gory Junior emerge.
 * Doge Dark continues to spawn in 6.7~13.3-second intervals, while Gory Junior spawns in 16.7~23.3-second intervals. In total, there are 17 Doge Darks and 6 Gory Juniors.
 * After 20 seconds, another Teacher A. is spawned, and after 30 seconds, another Shadow Boxer K spawns.

Reference

 * http://battlecats-db.com/stage/s01149.html