Sarkhan, Fireblood is that turn 2-3 ramp card you want to be casting in Dragon Tribal, basically a superior Urza's Incubator since for most turns you'll only be casting one Dragon per turn and Sarkhan also mana-fixes and also can rummage for you if you don't have a Dragon spell to cast
In other words, what a seller may not want to keep in their collection anymore can benefit your collection and how you upgrade your decks
on the opponent's turn, then Synchro both of them into Loading
Some examples include: Blue Eyes White Dragon, Red Eyes Black Dragon, Summoned Skull, Gemini Elf, and Flame Swordsman
It has a lot of searching options, Lumineon V to maximize the odds of setting up when needed and Penny to counter a potential Mawile lock in late game