Intent: Have armor/new stats in the game that change play-style dramatically.
Reality: Will never happen. But hey ideas are fun so Ill post this instead of keeping it all in my head.

potential ideas:

Mad Scientist labcoat

new stat: empower ~ enhances pickup effects:

empowers effects: adds a cooldown to your vials making them permanent. Cooldown lowered per point of empower.

speed boost - leaves a powerful fire trail.

defense boost - spiked shield. (shielding/shield bash would have a spiked animation that deals damage)

attack boost - gives 2 points of attack speed or CTR OVER the cap.
( upon obtaining all 3 speed,defense and attack boost types the effect would be shared with your entire party for 10 seconds)

Hearts - running over hearts causes them to explode and apply a mini seraphynx like heart attack

Vita-pods - When first picking up a vitapod you get 6 extra HP that wont regen. I you lose that extra hp in battle then it wont be recoverable.

Pills - 50% Heals whole party .

Remedies - immunity to cleared effects by 5 seconds per point ( up to 30 seconds max) ( remove fire, get temporary fire immunity, etc)

Vials - now hit like trucks with prolonged/increased status effects.

Barriers - barriers now stackable and give short speed boost ( stacks over movement cap)

Mecha Knight Kit - Self Destruct. Activate a second time to expend the robots remaining time/hp to do massive explosion damage.

Ranger Signal Flare - turns into Marshal Signal Flare: summons Desna the leader of the recon rangers. The area of effect and duration of the damage buff would be larger/last longer.

Artillery Strike - turns into one giant nuke that hits everything on screen.

Auto Turret Kit - turret becomes Controllable/mountable and does damage based on the armor star level of the knight in use.

Ocarina of Slime - your jelly absorbs other jellies and grows, gaining new abilities!

Pots - Have a chance to have scarabs swarms or snakes hiding inside of them that viciously attack whatever they hit.