Like most Magic: The Gathering cards, the value of Tamiyo's Safekeeping depends on a few consistent factors: its rarity, the printing and finish (regular or foil), its physical condition, and the set it was printed in (Secret Lair Drop)
When you do, create [c]Marit Lage[/c] a legendary 20/20 black Avatar creature token with flying and indestructible
Then, shuffle your deck.[M][+] Altered Creation-GXFor the rest of this game, your Pokmons attacks do 30 more damage to your opponents Active Pokmon (before applying Weakness and Resistance
Aside from turboing out a Hive Mind, though, you can also get games where you drop a Gideon of the Trials, make an emblem, and then start dropping Giants onto the battlefield for free with Force of Will-style counterspell backup from Pact of Negation
The Commander: Szarekh, The Silent King Out of the four face commanders for the Warhammer 40,000 decks, Szarekh, The Silent King is probably the least impressive, at least in isolation