A lot of artifact strategies rely on cheap artifacts to get rolling, so playing Meltdown for 2 mana and wiping out multiple cards on an opposing player's board is very reasonable, sometimes bordering on game-winning
As a baseline, he's a powerful midrange commander who gives great value to tokens decks - but he's also a combo enabler
For example, many Faeries in the old sets were green
While effects like this can be incredibly powerful when it comes to stopping combos or keeping players from getting too far ahead of the table, its important to make sure that they dont also detract from your own gameplan and harm you in the process
Finally, colorless cards, such as some artifacts, do not have any colored mana requirements but still require a general amount of mana to be spent to play
If youre able to keep resetting Riptide Gearhulk, you can keep tucking away your opponents permanent third from the top of their deck