(One preposterous example: a creature that cant be blocked as long as the spellcasting player is wearing denim.) See also: 'Magic: The Gathering Arena' Closed Beta Play Begins Now First came 1998s Unglued, then 2004s Unhinged
Gargos still remains relevant even once you've assembled your mountain of mana, thanks to its second ability
Then, select the deck you want to personalize, and when editing that deck, go to More Details, to the right: Notice that sometimes you may miss and to the Sideboard (which is right above More Options), but what youre looking for is the screen shown below: Within a deck's details, you can set individual preferences for companions, sleeves and avatars for when you play that deck
Everyone underrated this card the first time around, in Theros block
In games where you dont have enough lands or the right colors to cast them, they fix that problem