Urborg, Tomb of Yawgmoth exists to fix your mana, but can also fix your opponents mana depending on the colors they are playing
Most combo decks are easily disrupted by the Decay and with it being instant you can usually engineer it to net you more card or tempo advantage than Dreadbore or Vindicate
To determine the total cost of a spell, start with the mana cost or alternative cost you're paying, add any cost increases, then apply any cost reductions (such as that of Dirgur Focusmage's first ability)
Lately, Ive been picking the brain of our fantastic editor, Adam Styborski about this very issue
Nintendo and Top Seika already had a licensing deal set up for Super Mario since 1985
The mana dork has always been a quintessential card in almost any green deck