Its quite easy to break them down: Yuriko is a cEDH deck and a popular casual deck
And for the veteran TCG players, decks like Emerald and Ruby or Steel and Sapphire provide interesting combos and unique lines of play
The basic version of the card is essentially worthless: it's just not a very good card in competitive magic
Magic has a ton of creatures that do things whenever they come into play, and Conjurer's Closet ensures that they come into play again at the end of your turn
Nonetheless, Mirran Crusader is an incredible aggressor against Golgari (Green/Black) and Jund (Green/Black/Red) decks thanks to its protection from green and black
For example, if a +1/+1 counter is put on a creature you control, then you cast Botanical Brawler, then another +1/+1 counter is put on that first creature, Botanical Brawler's last ability won't trigger