Normally you would lose cards by Summoning this card then later Summoning 2 monsters, but if you Summon "Gladiator Beast Bestiari" and any other GB monster, you can gain advantage by destroying a card, then summon "Gladiator Beast Gyzarus" to destroy two more.
This generates even more advantage if you summon a Gladiator Beast monster that has an "on summon" effect such as Darius, Equeste or Murmillo before summoning Gyzarus.
Although "Gladiator Beast Heraklinos" is generally the better option if you have three material monsters to use, this card is perhaps more suitable when you have no cards in your hand, or when you need to set up a play for "Gladiator Beast Gyzarus". Although this card can prevent the activation of many cards that would nullify it, it may still be vulnerable to spells or traps that do not activate when it is attacking. For that reason, cards like "Trap Stun" or "Dark Bribe" might be advisable if you plan to use this instead of Heraklinos.
This card can be immensely useful in certain matchups:
Against Bujin decks, this card prevents the use of "Bujingi Crane" and "Bujingi Sinyou". In addition, due to the Bujin monsters' generally average base ATK stats, this card proves useful for swinging over their monsters.
Against Madolche decks, this card prevents the monster destroyed by this card from returning to the deck (or the hand if "Madolche Chateau" is in play), eventually causing them to run out of resources; however, be aware that a new copy of "Chateau" can recycle them on its own, also being in the Graveyard makes them an easy target for "Madolche Queen Tiaramisu".
This card proves especially useful against "El Shaddoll Construct". "Construct"'s effect during the damage step to destroy "Nerokius" will not activate, also only "Construct" will be destroyed as a result of "Nerokius"'s effect, and "Construct"'s recursion effect will not be able to trigger.