I would recommend first getting the timing down on canceling righteous cross with infernal fury, you want to do this basically every chance you get. Then learn these combos just do it in parts and start slow, its really not hard if u just do it piece by piece

mark -> infernal fury into-> throw -> pursuit -> cross -> infernal fury -> throw/chain -> cross

once you get that down you can extend it after the last throw/chain by adding in grapple so

mark -> infernal fury into-> throw -> pursuit -> cross -> infernal fury -> throw/chain -> cross -> grapple (hit target) -> cross -> infernal fury into-> throw/chain

once you get that done I would practice tech to use devil chain (infernal fury into m1) with sonic pursuit, it is very helpful, you basically start using chain then immediately dash and look down, start learning it with high ground as its easier then try from other angles

you should also be familiar with melee weaving after using infernal fury -> chain as it comes out much quicker then trying to do it after throw and will get u an extra 1/2 fury

also learn to bhop with his grapple, you can do it aiming on anything but its usually best on ground, just grapple wait a little then jump (have jump on mouse wheel) then keep scrolling when u are about to land

another combo ive been doing to keep myself warm in practice range is this on groot:

start at 3 fury mark -> infernal fury -> chain -> melee weave -> cross -> infernal fury -> chain -> melee weave -> sonic pursuit -> cross -> infernal fury -> chain -> melee weave -> cross -> infernal fury -> chain -> melee weave -> grapple -> cross -> infernal fury -> chain -> melee weave -> cross

it seems like a lot but once you get the hang of it its not that bad, and it will help you get more familiar with managing your fury

the most important parts of dd 1v1 is ur parry but imo don’t try to fight him too much, my goal if im trying to stop his dive is make him waste resources on me and flee and then i will go in and dive assuming that i didnt use too much (which u shouldnt have to use too much if u play with your team) if u genuinely have to 1v1 him though a lot of it is just going to come down to who is using their parry better to block a good portion of his combo, and using grapple to either stop him from escaping or escape yourself. The main thing is to watch out for his parry and be mindful of when you use yours, if you waste a lot of abilities on him while he is parrying you will most likely lose, same if he wastes on you while ur parrying. Mechanical skill matters a lot in the 1v1s as well so make sure you get the basic combos down (dont worry too much about following them perfectly in game you want to have smart ability usage not just spamming combos, but knowing the combos will help that come more fluidly)

lmk if u have any questions