My favourite build especially in 1-player mode is like this, whenever in normal battle or in boss battle(even boss rush).
Tips:
Weapen that have: Counter-attacks with X+Drains HP from targets(not necessary if you find Regen enough)
Hat: Horned Helmet(no remix)/Spartan Helmet(remix)/anyone if you equip Berzerker(remix) as an trigger of berserk(status)
Armor: Turtle Gi
Flairs: The Tr*force/Green Cross/Fairy/Tetromino/Pixel Glasses/The One R*ng(remix)
Video link: https://www.bilibili.com/video/BV1sJ411771L
Btw, what's your favourite build?