gee, agnaktor is really tough

MY LONGSWORD WITH GREEN SHARPYYY IS JUST BOUNCING AT HIs armour :O.....

once the magma on his body turns black, then any sharpness will bounce off of him. if your having problems try bringing pitfall traps, and enough materials to make 2 more. when ever he falls into a pitfall trap, his armor remelts making it easier for you to hit him without bouncing. also, bombs will remelt his armor as well, but only the parts that it expoldes next to. if your still having trouble, try using a bowgun or bow as tey aren't stopped by his shell.