More sideboard material. It will stop anything mid-range (3-5
power), outside of deathtouch or unblockable creatures. 4 converted
mana, with only 1 white mana required, is a low cost for that
strength of defense. The primary downside you'll find, in using any
wall, is that it can't be used to deal damage (unless an effect allows
it to). For that reason, I would categorize walls as non-creature
spells, in terms of effect. When balancing your deck, this will be an
odd factor - you would want to compensate with extra damaging
creatures, and factor Sunweb as part of your non-creature spell
base. Using a significant amount of creatures is always important, if
you are relying on them for damage. I generally use at least a 5/4
ratio of creature to non-creature spells. If you allow it to get too
close to 1/1, or are using less creatures than non-creature spells,
they won't be a fundamentally sound source of damage. One thing
to note, is that a card like this is useless against anything that
doesn't use creatures to win. Black and red can deal damage with
non-creature spells, and blue has the ability to destroy your library.
In that case, it might be better to use healing spells, or planeswalker
and enchantment destruction. Most players will rely on a strong trick
to win, so be prepared for the extremes. In truth, I'd like to see this
go away. Playing against subtleties, rather than over-powered
onslaughts of a particular variety, would be much more interesting.
The power of trick-play causes the game to be rendered a gambling
scheme, the extremes making the factor of luck much more present.