Credit: Wizards of the Coast Summon: Titan BPhillipYork: 5 mana for a 7/7 for a couple turns is okay
The more powerful and flexible your opponent's deck is, the more damage you can do when you are handed the reins
Key to the City 6.5 Ticks a lot of the boxes you want from your discard outlets and has a few more bonuses on top of that
It is more exciting to play this later in the match-up, when you have at least an extra two mana to pay for the second ability, so you could attack with more power and not be afraid to lose a land or two in case your opponent pulls out a sweeper
For example, [c]Kess, Dissident Mage[/c]s color identity is blue-black-red, because its mana cost consists of those three colors
If that pays off and the sacrifice is that 1-in-1,000 games of Limited go to turn 500 in an endless loop of omens, that seems worth it