The only thing left to them are battles, lands, and planeswalkers, all card types that typically dont have strong ways to interact with the board or spells when it's not their turn
Almost every other kind of interaction in Magic encourages you to think in terms of lining up specific threats with effective answers
For just one green, one white, and one blue mana, you could web-sling in anything from a Progenitus to a Jodah to an Atraxa
We Could Be Immortals, card number 219, is a Song card (appropriately, given that its the name of the Fall Out Boy song that plays over the end credits of the animated super hero movie, Big Hero 6)
There are more black creatures than gold ones and colourless combined however this doesn't take account of the reduction in black creatures you will encounter when you are black and thus able to play Ultimate Price or Doom Blade