Some Pokemon gain life steal at lvl 5. Life steal grants health equal to 5% of the damage you deal with basic attacks. This upgrades to 10% at lvl 9 and 15% at lvl 13. The following Pokemon have life steal: Charizard, Machamp, Lucario, Garchomp, Greninja, and Cinderace.
When mining on Battlefield or Omega stages, the order you obtain materials is always the same. Mining on the ground or on platforms makes no difference. Here's a quick chart I whipped showing the first 40 mined materials.
