Multiclassing and feats

If I am a beserker - Barbarian (Berserker) Defender and Striker Martial Strength, Dexterity Heroes of the Feywild

Can I use 'martial class feats' ? -

Wicked Blade
Paragon Tier
Prerequisite: 11th level, any martial class
Benefit: Whenever you use a heavy blade to make a melee basic attack, you treat the weapon as having the high crit property.
Published in Martial Power 2, page(s) 144.

jibuki wrote:If I am a beserker - Barbarian (Berserker) Defender and Striker Martial Strength, Dexterity Heroes of the Feywild

Can I use 'martial class feats' ? -

Wicked Blade
Paragon Tier
Prerequisite: 11th level, any martial class
Benefit: Whenever you use a heavy blade to make a melee basic attack, you treat the weapon as having the high crit property.
Published in Martial Power 2, page(s) 144.

If your main class or second class picked up from a multi class feat is considered a "Martial" class, then you can use the Martial feats.

In the Character Builder, take a look at the class and it'll tell you the Power Source.
Barbarian: Power Source = Martial
Battlemind: Power Source = Psionic
Fighter: Power Source = Martial
Paladin: Power Source = Divine
Swordmage: Power Source = Arcane
Warden: Power Source = Primal

Looks like your Barbarian can use them.

It doesn't show up in character builder.

Load a character, click on "1:Select Class", click on the class.

It'll display the role and power source:

But that is tied to your main class not including multiclassing?

I couldn't find the specific rule, but I know the Character Builder will allow you to take feats specific to a Power Source if you qualify though a multiclass feat.

Aya took the Warden multiclass feat and can now qualify for Primal feats, Paragon Paths, and Epic Destinies.

Agree, w Ken. Deslocke from the Dragon Series game is a Cleric, but multi-classed into Ranger and the Character builder lets me take all the Ranger feats (and nearly all my feats are Ranger, not cleric feats).