If you Special Summoned the above Level 5 monsters, you can Normal Summon "Rescue Rabbit", activate its effect and Xyz Summon "Number 39: Utopia" in the same turn; then, activate this card's effect and add a "ZW -" monster to your hand and equip it to "Utopia".
It's recommended that you add "ZW - Tornado Bringer" to protect "Utopia" from some card effects, to, in your next turn, add another one "ZW -" and moreover equip it with "Leo Arms" and get a "Utopia" with 7000 ATK or more.
If you only control a "Utopia" monster at the moment, "Photon Slasher" can be a great aid since it is Level 5 and Special Summons itself when you control an Xyz Monster.
You can overlay "Photon Slasher" with "Star Drawing" to Xyz Summon this card, allowing you to draw 1 card.
After sending this card to the Graveyard to allow "Utopia" attack again, you can activate "Xyz Reborn" to attack a monster left over, or rather just activate this card's effect to add another "ZW -" and equip this card to "Utopia" again.
If you already control a "Utopia" monster when you Xyz Summmon this card, use this card's effect to search for "ZW - Lightning Blade" and equip that monster to "Utopia" immediately. Then this card will be protected from card effects even while it's in the monster card zone. That will maximize the chances of allowing you to use this card's effect one more time on your next turn before equipping it to "Utopia" as well. If you don't care and equip this card right away, win-win because now you have a "Utopia" with more than 4000 extra ATK that can't be destroyed by card effects.
If you have both "Wind-Up Magician" and "Wind-Up Shark" in your hand, Normal Summon "Magician", then Special Summon "Shark" from your hand. Activate "Magician's" effect. Special Summon another "Magician" from your Deck. Then use "Shark's" effect to increase its Level by 1. Then trigger the 2nd "Magician" effect. Special Summon "Wind-Up Soldier", "Wind-Up Dog" or "Shark". Active its effect to make it Level 5. Overlay both "Magician" to Xyz Summon "Number 39: Utopia". Then overlay "Shark" and another Level 5 monster to Xyz Summon "Leo Arms".
Use simply a combo of "Photon Slasher" and "Gagaga Magician" effect for Summon this card.
"Leo Arms" is one of the only, if not the only "Zexal Weapon" that does not have the limitation "You can only control one...". If you can manage it, try to summon more than one to field to equip to your "Utopia" monster. You do not gain an additional attack for each "Leo Arms" you send to the Graveyard, but while equipped, each one will grant an additional 3000 Attack, easily pushing your "Utopia" monster above any opposing monster.