Jared Carthalion is one of those cards players keep asking about. Here is, in plain words, what its official text says, the rulings published by Wizards of the Coast, and the combos players actually run.

Official card text

+1: Create a 3/3 Kavu creature token with trample that's all colors. −3: Choose up to two target creatures. For each of them, put a number of +1/+1 counters on it equal to the number of colors it is. −6: Return target multicolored card from your graveyard to your hand. If that card was all colors, draw a card and create two Treasure tokens. Jared Carthalion can be your commander.

How it works : Jared Carthalion

Original English text — Wizards of the Coast / Scryfall

No additional ruling has been published for this card.

Interactions with other cards

These cards' text mentions Jared Carthalion.

Jared Carthalion, True Heir

When Jared Carthalion enters, target opponent becomes the monarch. You can't become the monarch this turn. If damage would be dealt to Jared Carthalion while you're the monarch, prevent that damage and put that many +1/+1 counters on it.