Wrexsoul is formed of the countless souls lost during the conflict one thousand years past...

Sun Titan

Vigilance
Whenever this creature enters or attacks, you may return target permanent card with mana value 3 or less from your graveyard to the battlefield.

Final Fantasy Commander

Tarkir: Dragonstorm Commander

Secret Lair Drop

The List

If a card in your graveyard has no mana symbols in its upper right corner (because it's a land card, for example), its mana value is 0.

If the mana cost of a card in your graveyard includes {X}, X is considered to be 0.

The mana value of a card in your graveyard is determined solely by the mana symbols printed in its upper right corner. The mana value is the total amount of mana in that cost, regardless of color. For example, a card with mana cost {3}{U}{U} has mana value 5.

A permanent card is an artifact, creature, enchantment, land, or planeswalker card.