Send "Galaxy-Eyes Photon Dragon" to the Graveyard as cost to Special Summon this card; then, search for "Galaxy Knight" and Normal Summon it in order to Special Summon "Galaxy-Eyes Photon Dragon" and Xyz Summon a Rank 8 monster.
This card can be used in a "Cyber Dragon" Deck to Summon a Rank 5 monster.
Search for another copy of "Galaxy Soldier". Use its effect to Summon itself, then Xyz Summon a Rank 5 monster.
Alternatively, another "Galaxy" monster can be searched, and activate "Galaxy Expedition" in your hand, Summoning another copy of this card.
Search "Galaxy Serpent" using this card effect. Then, they can be used to Synchro Summon a Level 7 monster.