Who was responsible for influencing not only Sonic Syndicate but also the genre death metal?
Sonic Syndicate:  They are influenced by Swedish melodic death metal bands such as In Flames and Soilwork and American metalcore bands like Killswitch Engage and All That Remains. In Flames:  Along with the bands At the Gates and Dark Tranquillity, In Flames was originally a metal band responsible for developing the genre now known as melodic death metal.
In Flames