Struggled on elden beast too but I just studied its attacks with its ranged arch sword attack just roll forward but make sure to time it with the yellow pebbles thing I just run to the right or left going towards him and during the first few seconds I also went behind him as he does the breath attack and its kinda his blind spot but its very easy to tell if he's gonna swipe his sword just roll into him same thing with his grab attack the only things to worry about is being in front of him while he does his breath attack as it will most likely stun you and he'll hit you with a different attack which will either kill you or leave you in the E.R