Fairly niche card, even when you play with it you usually don't want to have to find it and play it, but as it is the best at doing what it does it has retained its main cube slot
It plays in a similar space to sacrifice, with the upside of providing red mana if you need it
Floodborn characters are much more powerful versions of characters, affected by the flood of ink that happened in Rise of the Floodborn in some way
That might be card advantage from cards like Underworld Breach, Muldrotha, the Gravetide, and Osteomancer Adept, or it could be creature-based rewards from the likes of Sidisi, Brood Tyrant
Red has a primordial, burning aspect to it already - why not cast some spells with mana forged from the very dawn of the planes