After Mega Man defeated "Cut Man Shantae", she got turned back to normal and brought Shantae into Dr. Light's Lab to heal her. He destroyed the 1st Dark Crystal, so Dr. Wily can't use it to rule the world. Mega Man went into Marble Zone and entered the dungeon. Mega Man found the 2nd Dark Crystal, but Guts Heavy came in and he blocked the 2nd Dark Crystal from Mega Man into destroying it. Guts Heavy was about to bring that shard to Wily so he could conquer the world. Mega Man doesn't want that to happen. So, Mega Man has to fight Guts Heavy to destroy the 2nd Dark Crystal. He is ready for a "Rumbling" Battle against Guts Heavy Controls: Arrow Keys to move, as usual. Press Z to jump, and if holding the down key, you'll slide, but it literally has cool down. Press X to shoot/use the current weapon.
Update 1/7/2021: I use 15.ai for Guts Heavy's voice and the dialogue for Guts Heavy has changed. Update 6/17/2020: Added Cutscenes and Heavy has a new Taunt/idle animation and he has new sounds. Update 2/23/2020: Mega Man Updated with new animations. Update 3/21/2020: New Health Bar! Credit to NeonScratcher1275 for the original Guts Man Boss battle and Xstables for the A.I. of Guts Man. Note: The 8 Dark Crystals are rare crystals that Wily could use to rule the world and become unstoppable. These crystals have Dark power that Wily could use and these 8 Dark Crystals are concealed for thousands of years. These 8 Dark Crystals must be destroyed, because no one should possess the dark power of the 8 Dark Crystals.