Hiryū no kokyū

when you activate this feat your sword immediately gets the flame tongue attribute. you have 6 different forms(attacks) to use. This feat levels alongside you. 

level 5: first form roaring dragon.  you swing your sword at a low angle and then swing the sword horizontally. does 2d10 damage and uses 1 of your attacks lunges you forward 15 before use

level 7: gain another attack. second form blazing sky. you perform a spinning attack twice and then perform an upward cut.  does 4d10 damage uses 2 of your attacks

level 8: seventh form retribution: you charge forward up to 25 ft then you slash down on your opponent's shoulder and then you aim for the neck with a horizontal slash. does 4 d10 and uses 2 of your attacks a crit decapitated the opponent 

level 9: gain another attack. third form dragons fury. you deliver rapid slashes to your opponent. does 6d10 damage and uses 3 of your attacks

level 10: ninth form dragon ascent: you jump up high and descend on the target while performing a horizontal spinning attack all the way down(the spinning attack part has you upside down). does 6d10 damage and uses 3 attacks you must succeed a dex saving throw or take 1d20 damage.

level 11: gain another attack. fourth form fiery dance. you attack with your sword while moving as if you were dancing at the end of the dance you deliver a stab. does 8d10 uses 4 of your attacks

level 13: fifth form dragons breath. you perform a horizontal slash and unleash a gale of fire from your slash. range of 20 ft and does 2d10 damage uses 1 of your attacks

level 15: gain another attack sixth form roar of 1000 dragons. you begin by lunging forward up to 25 ft then you deliver a low-angle slash followed by the fifth form, next you deliver two spinning attacks and finally you deliver an attack across the opponent's torso and then a horizontal slash aimed for the head. does 10d10 damage and uses all of your remaining attacks. you need to have at least 5+ attacks to use this form. if you roll a critical hit to break ac then you decapitate your enemy.

level 17: eight form hiryu: you take a stance and your str, dex, and con are enhanced for 1 hour. takes an action and when it ends your hp drops to one and you are knocked prone.