2 BALLS (Bant walls 2.0)

this deck did surprisingly well at fnm, and is now being tinkered with to be even better. the mb and sb still need a little tinkering. i think luminarch ascension makes perimeter captain a lot more useful for life gain, making my opponent swing to avoid counters. explore is a little iffy here, but works well with overgrown battlement and helps even more with draw and getting summoning trap off faster. i want this sb to be ready for jund, mythic, and uw control (and even polymorph- the mage). any suggestions are greatly appreciated. i have thought about spreading seas, but im not really thrilled about the idea yet, it may grow on me more though.