If the card has any mandatory additional costs, you must pay those to cast the card
After that though, you could consider a lands-matter sub-theme, playing multiple lands a turn to stack up the triggers
The bad news for Rhox Charger is that you can just put a 4/4 with trample into your decks, so there are usually better options unless youre specifically looking to stack a bunch of exalted triggers
While we haven't seen God-Pharaoh's Gift yet, there are several graveyard-focused decks in the format, making Scavenger Grounds a good option for both main decks and sideboards
The way its cards chain together makes it that smidge more complicated than the Amber and Sapphire deck above, so its recommended for those players who already know the basics of Lorcana and are looking to dive into its more advanced strategies
Start off by dumping Equipment either onto the Battlefield or into the Graveyard, and cast a couple of stable blockers such as Danitha Capeshen, Paragon or Eowyn, Lady of Rohan, both of whom can attack with Vigilance and stay back as a blocker