For the first decade or so of their existence, not being able to attack was built into the rules of Walls, but as Magic has shown us time and time again, limitations breed creativity
Nemata, Grove Guardian, while expensive for a commander, also has the potential to be a huge threat at any point beyond the midgame as both token generator and payoff
As is the case with most complex decks, however, it is very rewarding to master the play patterns and win games with this sort of deck, so if you like puzzles and tutoring lands I recommend giving it a try
Avatar the Last Airbender will be here before we know it and the more spoilers that get leaked the more some of these might start to tick up in price
FINAL FANTASY Card Sleeve Series Lightning (FFCSS-06) View product details FINAL FANTASY Card Sleeve Series Lightning (FFCSS-06) $14.99 Presenting FINAL FANTASY card sleeves of Lightning from FINAL FANTASY XIII