If you have no monsters in your Graveyard, you can Special Summon "Mirror Ladybug" and use it in combination with one of the above cards to make it Level 7.
By using "Fallen Angel of Roses", not only you can Xyz Summon this card quickly, but you can also evade the banishment effect of "Fallen Angel".
You can Xyz Summon this card with less effort in a "Gladiator Beast" Deck provided when you run two copies of "Gladiator Beast Octavius". After "Gladiator Beast Gyzarus" battles and activates its effect, simply tag it for 2 copies of "Octavius", activating their effects to destroy two of your opponent's Set Spell or Trap cards. Overlay your two "Octavius" to Xyz Summon this card, eliminating the need for you to worry about their drawbacks. Note that you can revive "Octavius" as a free beatstick by using "Gladiator Beast Darius".
You can also use "Gladiator Beast Secutor" in the same way to get the two copies of "Octavius" and summon this card.
Alternatively, since "Coelacanth" is also Level 7, you can use itself as Xyz Material.
Use "Forbidden Chalice" on this card after using this card's effect. That way not only will this card attack due to its effect being negated, but will also gain 400 ATK, as well as the monster you gain control from your opponent.
Use this card's effect to gain control of(one of) your opponent's Monster(s) and Tribute them both to summon "The Tyrant Neptune".