Simple suggestion here:
Knockback vials would be similar to other vials except that it deals no damage and deals no status effect.
However, it deals knockback to enemies similar to reviving (without dealing stun).
Would be perfect when trojans cornerblock you.
Shield capsules are similar to health capsules, except that they give you shield health instead of normal health.
I'm not elaborating further in exact numbers because I just want to get the concept through.
Stun vials cause knocback and stun already.
Trojans are almost imprevious to frontal attacks so they'll never get knocked hard.
By the time the animation of the shield pill gets done, a regular shield would almost heal by itself. It doesn't take too long.