It allows you to grow your creatures to unlock board stalls, while enabling some very interesting synergies by dishing out creature abilities to your team
On the surface, your creatures grow larger every time they survive combat or other types of damage, which is still pretty good, but playing Rite of Passage with a few other cards can turn your Dinosaurs into a huge threat
The second-most popular deck is nearly as cheap too
What kinds of cards will have flashback
They always produce two mana in a combination of your commander's colors, but you need to pay one generic mana to get two colored mana back out
This very effective enchantment turns a creature, land, or planeswalker into a colorless land that can tap for only generic mana