Complex sentence: Letran College joined the NCAA (Philippines) league in the 1928--29 season, taking a knight as its mascot in respect to its founder, the Spanish officer Don Juan Geromino Guerrero, who was a Knight of Malta.
Split into simpler sentences: Letran College joined the NCAA (Philippines) league in the 1928--29 season, taking a knight as its mascot. The choice was made out of respect for its founder, the Spanish officer Don Juan Geromino Guerrero, who was a Knight of Malta.