Just think about a mechanic where your 3 guard indicators get cracked after blocking several attacks from that direction to the point where they collapse.
Light attack = 1 dmg on that indicator side.
Heavy attack = 2 dmg on that indicator side.
Guard break = 0.5 dmg on all 3 indicators.
Let's say vanguards and hybrids have 3 hp on their indicators, heavies have 4 and assassins have 2.
Indicator health regenerates in a similar manner to shugoki's hyper armor.