Rage: provide a buff that gives ammo regen and healing, similar to that of a level 3 dispenser, for 10 seconds.
480 damage needed to build rage

-40% damage taken from rocket jumping
-20% falling damage
on rage: -80% damage taken from rocket jumping
-40% damage fall damage

what about
+take no fall damage
when buffed:
weapon knockback increases to 120%
low gravity
but 10% slower movement speed
needs 500 dmg to activate
20% knockback vulnerbility
10% less self inflicted dmg

how about just a cosmetic?
that people can claim from an achievement or a case?

When activated you to take -75% less self damage and -90% less fall damage