"Phantom of Chaos" can also copy the effects of "Immortal Phoenix" this way, clear out your opponent's field before Summoning a copy of "Sphere Mode" during the End Phase, ignoring its Summoning Conditions.
Use monsters such as "Marshmallon", "Spirit Reaper", and "Aroma Jar" that cannot be destroyed by battle, which will ensure you will have plenty of monsters to tribute for "Ra" if they are not destroyed by card effects.
You can also use "Aroma Jar" in combination with "Poison of the Old Man", "Nimble Momonga", and "Spell Absorption" to quickly gain a lot of life points in preparation for summoning "Ra" with at least 20,000 ATK. These cards can also be used to regain LP paid for the cost paid when you Tribute Summon "Ra" within a few turns. At least one copy of "Aroma Jar" should be left on the field in case Ra is destroyed.
You can "The First Monarch" to Tribute Summon this card with one less tribute by declaring DIVINE as its type. However, this can be tricky if you do not already have 3 or more monsters to tribute, though as declaring DIVINE to change its Attribute would prevent yourself from Special Summoning any monster whose Attribute does not match, like the commonly used Tribute fodders "Level Eater" and "The Tricky".
Use "Power Frame" to make this card have the same ATK as a monster your opponent controls without the need to decrease your LP to be able to have enough ATK to stay alive and destroy monsters on the field.
If two "Flint Locks", "Flint" and "Morale Boost" are under your control, then "Flint" can continuously be equipped, switching between the two "Flint Locks", while "Morale Boost" gives yourself 1000 LP each time it was used. This can be repeated infinitely, effectively giving yourself access to an astronomically high LP. By using "Inferno Reckless Summon" to get 3 "Flint Locks" on and doing the loop, they can then be Tributed to Summon this card after gaining enough LPs for an OTK.
If you run a swarm deck, it is best to have this card in your side deck in case your opponent has "The Winged Dragon of Ra - Sphere Mode", so you can use its effect to benefit you before it can be returned to its owner.