Back when the Mythic Map Pack launched there was a new achievement released for collecting the skulls scattered around each of the new maps. I figured that these skulls should have toggled new effects. Sadly Bungie couldn’t make that a reality.
But you can 343.
These are the skulls and these are the effects I have come up with for them:
-Orbital Skull: Map is now in low gravity.
-Assembly Skull: All enemies are replaced by Hunters (or their equivalent in H4)
-Sandbox Skull: When the campaign level or firefight game starts a forerunner unit spawns and slowly begins to follow the player, if it reaches them it instantly one shots them with a huge and powerful beam
-Heretic Skull: All enemies wield UNSC weapons, all players and allies wield Covenant weapons.
-Longshore Skull: All weapons are replaced by various fish that shoot blasts of water instead of bullets. Different weapon means a different fish (one fish must be a cod) all the way up to orcas for rocket launchers.
-Citadel Skull: Players spawn in a Forerunner combat suit and all enemies are Flood.