Return of Reckoning

Guys i'm totally newbie on this class. Do I need to switch mutations during the fight to access to the skills?
Or just it depends from the build?

Soem skills are available in every mutation some only in two, some only in one etc...

Just hover over the skillicon with your mouse and you will see "Requieres gift of Monstrosity/Brutality/Savagery"

You will have to swap quate allot between Savagery and Brut to make optimal use of the mara.

Not If u play aoe debuff Maschine

To make the most out of a marauder you'll need to change mutations fluidly. Your resting/roaming stance should be monstrosity as it affords you a defensive buff and a heal in reactionary circumstances when someone gets the jump on you. When you see the enemy first you have time to activate ferocious assault and apply thunderous blow, which is a GCD in which you can potentially ignore enemy armor pen and heal yourself for 200 HP while switching to savagery and then applying cutting claw. You've now applied your self buff, potentially significantly reduced the damage of your enemies first ability and you haven't hur reduced the damage potential of your rotation at all. Your next priority is either heal debuffing, draining swipe or toughness debuffing followed by rend spamming until you're either needing to get out of dodge, de taunt, snare break and run away in monstrosity, or immediately switch to brutality and impale your target until they're ready for your guillotine. Because guillotine is on a 10s cooldown, it's usually very important to immediately switch back to savagery in order to keep your wounds, armor and heal debuff applied in order to help your team mates chop your target to pieces.

In a perfect rotation you'll have used two abilities in monstrosity, five in savagery, two in brutality.