This monster can be a good combo against monsters with 4000 ATK or more, using this card and having "Battlin' Boxer Lead Yoke" on your side of the field and "Oni-Gami Combo" in your hand. Use the effect of "Oni-Gami Combo" on "Lead Yoke", then let it attack your opponent's monster with 4000 or more ATK, twice, activating "Star Cestus'" effect in the process.
A card that can combo well with this is "Twin Swords of Flashing Light - Tryce": use it on an already weak "Battlin' Boxer" and let it attack an opponent monster twice, while using "Star Cestus'" ability twice. If you plan on finishing the opponent in this turn, equip the opponent's monster with "Mage Power", "United We Stand" or "Mask of Brutality" (the latter is preferred cause you can easily get rid of it by not paying the cost).
With this card's effect, you can go up against "Ally of Justice Catastor" without worrying about your "Battlin' Boxer" getting destroyed.
Although chances of encounter are low, this card can make full use of its effect against Water Dragon, especially if you are able to attack with multiple Boxers, which would inflict 8400 damage if all of this monster's Xyz Materials are used in one turn, or use Assault Armor, inflicting 5600 damage to your opponent. Even this card's evolved form Number C105: Battlin' Boxer Comet Cestus can destroy that card, inflict damage and make it miss the timing.