You should consider that working extra hours may have a negative influence on your health.
In the shadows you still echo. Your echo leaves the shadows and hits people, creating an influence on them. You're like the shadow person pulling the strings, making things do what you want... influencing them.
This is a jukugo word, which usually means on'yomi readings from the kanji. If you know the readings of your kanji you'll know how to read this as well.