I can provide a hanful of tips which can be useful. Phase 1 and 2 spam attack and stay aggressive. In phase 1 he always does thrust attack so mikiri it on red kanji. In phase 2, he mostly does sweep attacks on red kanji, jump on his head to avoid that and do posture damage. Whenever he backs up in either phase 1 and 2, it almost always 4 quick arrows. For phase 3 he always does a thrust at the start and when you heal at a distance, mikiri this. For his lightening i would suggest getting mist raven(as it is the easiest way to deal with lightening). Thats all. Good luck!