Complex sentence: Instead of hiding and standing from the sidelines, sending his/or magic power for the magical doll to do his/her "dirty work", Shindou and Tomiko instead fight together, therefore increasing the strength of Tomiko.
Split into simpler sentences: Instead of hiding, and standing from the sidelines, sending his/or magic power for the magical doll to do his/her "dirty work". Shindou, and Tomiko instead fight together, therefore increasing the strength of Tomiko.