Tips from the Pros!

Hey guys

my character Chimernaut is slaying but i cant seem to kill shaper easily although ive reached delve upto 390 killing ahutotli and Kurgal. Any tips on what am i doing wrong? im using a pdps 399 one handed sword ,6l loreweave and farming t16 maps with ease just dont know what im doing wrong that i cant kill shaper

:(