mtg commander masters deck list Magic The Gathering - Commander Masters Precons Decklist and

While Ral Zareks ability is generally more powerful than casting Time Stretch, the marginal utility of a fifth turn over a fourth is generally not as great as the first extra turn over zero

Coralhelm Commander Coralhelm Commander starts out as a simple 2/2 for 2 mana, but with level up, it quickly grows into a flying threatand more importantly, at level 4 or higher, it pumps all your other merfolk with a +1/+1 bonus

Jaya, Venerated Firemage Image 15

Giving decks these tools would make them too powerful, and are kept out of the format

The amount of life you lose is determined by the mana value of the card in your graveyard, not the creature once it's on the battlefield