While changing the colors of stuff is rarely worth it on its own, the major benefit these cards have is that they are capable of targeting every creature on the battlefield for only a single mana
I know Dragons have a lot of support, but I think these came out really well
There aren't many two mana tutors that don't cost a card to use and offer this kind of flexibility, but most creatures are valuable because they are efficient rather than because they are the right tool for the job
Are you using Garura, Wings of Resonant Life from the 25th Anniversary Tin: Dueling Heroes? Now you can Summon Garura and get a free Synchro Monster to clear the way for Garura to attack directly and do double damage
From Academy Elite drawing us cards in exchange for counters to Zameck Guildmage also drawing us cards in exchange for counters, we ask which resource wed rather have
If both these effects arent enough, Palantir of Orthanc deals damage based on the mana value of the milled cards