Fire Sages Fire Sages' red mana generation is cool, but being able to use that mana to power itself up--assuming you can pay the rest of the ability cost--could turn it into a powerful attacker in a hurry
Evendo, Waking Haven + Uthros, Titanic Godcore The station lands vary wildly in power level, but its pretty clear what they were going for with Evendo, Waking Haven and Uthros, Titanic Godcore
Read More: The 10 Best Flicker Cards In MTG 5 Geth, Lord of the Vault Why is Geth so cheap, its such a great Commander card
The other issue is that if you don't have a source of lifegain, ideally a Blood Artist effect, then you can be in danger of locking yourself out of the game
This is similar to the principle of card draw or burn, you just want the most efficient card because that plan is always a good one
Grim Haruspex Grim Haruspex is not just a decent-bodied creature for its mana cost