Idea [Class Concept] Barbarian

Hey guys, Draco here again.
This is another class idea I have. It's one of my older ideas, but I think this is an interesting one which requires a different gameplay style, but it may be a little unbalanced. So, without further ado, here it is.

Name: Barbarian .

Description: A proud clan of ancient warriors that triumphs over their vanquished foes.

Armor: (-#> these make sense later)
Helm: Diamond -1> Prot. I -5> Prot. II
Chest: Chain -4> Proj. Prot. I
Legs: Gold -3> Fire Resist I
Boots: Gold -2> Prot I.

Inventory:
1. Wooden Sword "Warrior's Path" (-2> Stone -3> Iron)
2. Bow [power I]
3. 3 Healing items
4. 64 arrows
5-7. Nothing
8. Compass
9. Nether Star "class selector"

Passive Abilities:
Ascension: The main ability of the barbarian is "ascension". Whenever a barbarian kills an enemy, he gains 1 level and better gear to fight. His armor and weapons both improve to better versions. This makes for highly decisive actions of which to kill or risk being killed.

Iron Hide: This ability is instakill counter. If a barbarian is killed by an instakill, the killer simply loses his weapon for 5 seconds. This leaves a small window of which an attacker would be left vulnerable and forces plays that work around this ability (e.g. Pyro loses axe, archer loses bow, assassin loses sword)

Active Abilities:
Ancestral Rage: When a barbarian reaches level 5, he gains the "ancestral rage" ability. All damage done will raise his experience bar (can never level him up). Once full after 30 hearts of damage dealt, chat will announce to you that you can use this ability. To activate, simply sneak-block and your character will explode and fire particles will surround you for 20 seconds. During this time, you have strength II and sword gains knockback 1, but you are weak for 1.2 damage. Cannot be activated with the flag.

Ok, so this is a little unbalanced and could use some suggestions on what to do to make it better. The problem is that It's hard to make a new class concept. You need to think of the counters, the overall standings of this class compared to others, it's overall role, etc. I hope to get some good feedback on this, so please, voice your concerns and suggestions. Thanks.

My other (more balanced) idea, Phantom: https://www.brawl.com/threads/50628/

Thanks for reading and be back soon(ish),
-Draco