If you have 2 “Solar Flare Dragons”, or a “Solar Flare Dragon” equipped with “Raregold Armor” and another Pyro-Type monster, your opponent cannot attack.
Even if “Solar Flare Dragon”’s Type is changed, as long as there is another Pyro-Type monster on your side of the field, “Solar Flare Dragon” cannot be attacked.
You can apply “Barrel Behind the Door” to the effect of “Solar Flare Dragon”.