Takuya mostly acts like a meatshield in protecting the main attackers but overall becoming an annoyance to the player. In later stages and three crown difficulty he becomes extremely tanky forcing the player to use high DPS units such as Cyborg Cat just to outrange him.
Strategy
Use units that can outrange and deal lots of damage to him, like the aforementioned Cyborg Cat, Dragon Cat and/or Sexy Legs Cat, just to name a few.