Ideas/Tutorials for a Kris Dark World Cosplay?

Hello! I'd like to go as dark world Kris for Halloween this year, but im not sure where to start! I have 0 experience cosplaying outside of having a sibling who knows how to sew!!! are there any direct kris cosplay guides online, or something to help construct the armor? im thinking eva foam from my very very limited cosplay knowledge but obviously ive never worked with that material before. how much eva foam should i get? one 500 x 1500 mm sheet? more? l