There were four warriors-matter cards in Khans of Tarkir (all in WB) and four Gates-matter cards in Guilds of Ravnica (one blue, one Boros, and two artifacts, which makes sense considering its the play-all-the-colors archetype)
Among the older Pokemon to receive a Mega Evolution was Sceptile, who gained a terrifyingly powerful tail and the Dragon typing
Not only does it give you graveyard value, but its a repeatable way to mitigate flooding
Hitting for 6 and paying 2 mana to destroy two lands is a good way to annoy players, especially in EDH
Latias is my favourite legendary and it's probably due to the Pokemon movie it featured in
Whether you mulligan slightly more or slightly less, so long as you're consistently falling in the "reasonable" part of the spectrum, you can feel like you're doing pretty well