Fire Nation Palace

Mana from firebending abilities isn't lost until you leave combat and go to your second main phase. It can be used at any time during combat, even after combat damage has been dealt.

"Firebending N" is a keyword that represents the ability "Whenever this creature attacks, add N {R}. Until end of combat, you don't lose this mana as steps end."

Multiple instances of firebending on the same creature trigger separately, each granting you the appropriate amount of mana.

If one of these lands enters at the same time as any number of basic lands, those other lands are not counted when determining if this land enters tapped or untapped.

Any other mana you add during combat will still be lost as normal when moving between steps of combat.

Firebending abilities aren't mana abilities. They use the stack and can be responded to.