Thankfully, we have ways to cheat on the cost, with Runaway Steam-Kin making our one-mana cantrips free as long as we can get it up to three counters and Dreadhorde Arcanist allowing us to flash back a cheap spell to further grow our Kiln Fiend
Its rarity and status as a big, splashy dragon make it a collector favorite
Theres a Hardened Scales which is nice, especially for Pioneer or Modern players who want some new fancy artwork for their decks
The prepared spell is not what you are here for, but it helps with one of the issues of running ramp in a control deck where the focus on efficient interaction means you can fall behind on card advantage
Jhoira eventually filled that slot in Dominaria , but Saheeli came back to also fill the slot she knocked out of the set the first time around
The Sprite is one generic mana cheaper, but its status as an uncommon versus a common can explain the mana cost