Not only does it add fun flavor to sets that are themed around characters going on quests, but these are versatile modal cards that can be very powerful
Once it leaves the battlefield, the card goes back to its normal self

Teleporter Trainer Rockets Secret Machine Uncommon 093/109: Venture Bomb Trainer Rockets Secret Machine Uncommon 094/109: Dark Metal Energy Energy Special Uncommon 095/109: R Energy Energy Special Uncommon 096/109: Rockets Articuno ex Darkness Rare Holo EX 097/109: Rockets Entei ex Darkness Rare Holo EX 098/109: Rockets Hitmonchan ex Darkness Rare Holo EX 099/109: Rockets Mewtwo ex Darkness Rare Holo EX 100/109: Rockets Moltres ex Darkness Rare Holo EX 101/109: Rockets Scizor ex Darkness Rare Holo EX 102/109: Rockets Scyther ex Darkness Rare Holo EX 103/109: Rockets Sneasel ex Darkness Rare Holo EX 104/109: Rockets Snorlax ex Darkness Rare Holo EX 105/109: Rockets Suicune ex Darkness Rare Holo EX 106/109: Rockets Zapdos ex Darkness Rare Holo EX 107/109: Mudkip Water Rare Holo Star 108/109: Torchic Fire Rare Holo Star 109/109: Treecko Grass Rare Holo Star 110/109: Charmeleon Fire Rare Secret 111/109: Here Comes Team Rocket

Tormod generates Zombies each time cards leave your graveyard, encouraging recursion, exile, or blink strategies
when you build your deck, you circle two of them and can then add one colour of either mana to your mana pool
In fact, I think with Force of Negation I hard-cast it about a third of the time, compared to Force of Will, which I hard-cast probably less than 10% of the time