Sense of to exist, be present is attested from c.1300. Meaning to pay for as a treat is from 1821. Phrase stands to reason (1620) is from earlier stands (is constant) with reason. Phrase stand pat is originally from poker (1882); stand down in.
In Expert Mode, Wall of Flesh is seen to be significantly faster than his prior speed, posing map navigating harder as the players are demanded to plan out their routes fasters. In addition, getting pulled by his tongue will inflict additional damage to the player, possibly killing a weakened player.
From Digimon Masters Online Wiki - DMO Wiki. Burst Mode is an additional evolution, equal or superior to Mega, that can be unlocked. These are called Side Mega or Burst Mode. Not all Mercenary Digimon have one. Below is a list of Digimon who can achieve Burst Mode/Side Mega.