You also need to do this if its returned to hand with a bounce effect like Unsummon, or if it moves to any other zone at all from the battlefield
UB can play off the same strong commons and uncommons as UR does, and it has some great expensive spells to pair them with like Sephiroth's Intervention, Ice Magic, Dreams of Laguna (flashback), and Sidequest: Hunt the Mark
The pre-made single-player decks for Whispers in the Well feature one for Sapphire and Steel inks and one for Amber and Emerald inks
4 Shelob, Dread Weaver Shelob is another card that becomes more dangerous over time, but it also provides exceptional utility even as it grows to become a larger threat
None of these abilities is necessarily preposterous on their own, but each gives a different option - and in formats such as Modern and Legacy (the latter of which this card is banned in) they build up into an insurmountable advantage
Its mana fixing