Version used : Pixelmon-1.12.2-7.0.5-universal
Problem: When battling a wild pokemon or trainer , either your own pokemon or the enemy pokemon can actually move the player when battling (attack animations). This can result in falling into bottomless pits , lava, or from a cliff. This is even more problematic when in Ultra space , Nether and The end for the sheer quantity of bottomless pits and lava included in these areas.
Suggestion: Make it so when you call the battle start event that it disable player collision entirely until battle end is called.