The reasons to not play Genesis Chamber have little to do with your opponent
First Upgrade Run, dont walk, to the shopping cart and pick up an Astral Slide
If you can't mill a card, you'll still follow the rest of the instructions of Ursine Monstrosity's last ability
Finally, not only will you fight against other trainers in real-time matches, but you'll also be able to fight against AI-controlled characters to improve your strategy technique and master your deck
Theres a lot of cards in the deck that benefit from having and playing this character type
(If this card is your chosen companion, you may put it into your hand from outside the game for as a sorcery.) Lifelink Once during each of your turns, you may cast a permanent spell with mana value 2 or less from your graveyard