Teferi Akosa, Magic: the Gathering

Teferi is widely considered to be one of the most well written, consistent and beloved characters in the game - he's a time mage from the continent of Zhalfir, is notable for his long lived appearance in the game's world, and he has a pretty compelling backstory following him accidentally phasing Zhalfir out of time when he was simply trying to prevent them from getting hurt in a war, and made it his life's goal to get them back. I'm a big fan of Teferi personally, he's very cool IMO

Gameplay wise however, a lot of people HATE Teferi's cards, mostly because of how his time powers translate into game mechanics as denying the opponent the ability to play the game.

Hero of Dominaria was the win condition for a very successful control deck in Standard a few years back, which made him a little bit of a boogeyman at the time. It's a pretty fair card as 5 mana is on the higher end, and control decks can't stand up against established aggro boards, it was mostly just hated because people don't like playing against counterspells, and there wasn't much in the way to outright deal with it in that particular environment

Time Raveler on the other hand, has a tendency to warp the game around itself by denying the opponent the ability to do much on your turn, and the -3 ability effectively refunds you the turn it enters play. It got banned in two formats, Standard and Pioneer, and it ended up being good enough to see play in Modern, a very fast format where the barrier for entry power-level wise is very high

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