Looks cool but the way summons are implemented in the demo very dumb. It has no real tactical or strategic value, and existing completely separated from other battle mechanics. If you're good, you'll never use them. If you aren't good, you'll be able to use it as a crutch for everything that is a bit hard, instead of having to improve your skills, tactics or strategies.

Let's just hope this is just a temporary implementation for this demo only.