
Very cool deck! Can I ask why Raging Phoenix is in the extra? I thought it would be for Zealantis OTKs but we aren't on Zealantis either.

I just want something to be a Fire-link target after summon Promethean Princess.
We can use Ferocious Flame Swordsman instead. Because Ferocious Flame Swordsman is link-2 Fire Warrior that easy to summon by using any 2 monsters with different names. And yes, You can use Nibiru-Token to summon him. Then use his warrior-body to summon Isolde. I used him sometimes and he's very good card.
On the Raging Phoenix side. He and The Amblowhale, Is the easiest big-fire body we can find. They both good for the deck. Raging Phoenix can revive himself with big stat and turn to be the good beatstick / finisher. Amblowhale can pop 1 card and revive any Link-3 or lower from the GY.