And, as for Stoneskin, Blink and Aquaveil being 'Spikes', that is incorrect. Ice, Blaze and Shock spikes deal damage to enemies. Aqua, SS and Blink doesn't. Regardless of how you think of them being classified Defensively or Ofensively.

So, therefor, SE should add in Terra Spikes to inflict Earth Damage as well as having the effect of Slow. Just like Ice Spikes having the ability of inflicting Paralyze. And there needs to be a Water Spikes and Air Spikes.

Water - Does Water Damage plus decrease an enemies ACC upon hitting you, while it is active.
Air - Deals Aero damage and lowers the enemies EVA upon hitting you, while it is active.

Or something like that.

Blink, SS and Aquaveil does not do additional effects as well.