Ok. The method I used is going to the jungle with a drax. You can find it in hellchest. Mine clorophite. Thus getting a clorophite claymore. Dying several times is normal. Then get any hardmode attainable armor (cobalt not recommended ) after you do this, if you explored a sky island in prehardmode use that bridge to farm wyverns. Doing this allows you to get wings, this making him easier to dodge. Then while you are up there summon the destroyer. Using Hermes boots, spectre boots, ect. is recommended. So you can run away. Since he is as fast as Hermes boots he should chase you down. Then jump off the platform down right above his body and farm hits. This method works for mobile only. Good luck.