Although this card's effect Special Summons a "Gladiator Beast" monster from your hand in Defense Position, this still allows yourself to activate/apply that monster's effect, as well as use it for Contact Fusion. For example:
This card's effect can be used to Summon a "Gladiator Beast Bestiari" from your hand, triggering its Spell/Trap Card destruction effect, then shuffle both monsters into your Deck to Summon "Gladiator Beast Gyzarus" and destroy 2 more of your opponent's cards.
This card's effect can be used to Summon a "Gladiator Beast Darius" from your hand, then use the effect of "Darius" to revive a "Gladiator Beast Laquari" before shuffling all 3 monsters into the Deck to Summon "Gladiator Beast Heraklinos".
Use this card's effect to Special Summon another copy of this card from your hand, and trigger its effect to Special Summon another "Gladiator Beast" monster.
With the above combo, it's possible to Summon 3 copies of this card plus another "Gladiator Beast" monster, allowing yourself to Xyz Summon a Rank 8 Xyz Monster.
This card can be used as a fodder for "Trade-In" or "Allure of Darkness" which somewhat gives "Gladiator Beast" a draw power that the archetype has been lacking in.