I disagree. You're combining Alarm, Aid, Protection from Energy, and - to some extent - Blindness and Power Word Stun with no HP limit. And those last two repeat. And you're dropping the Concentration requirement. This is far too powerful for a 5th level spell and should be an 8th level spell at least. You are getting 5 effects for the price of one.
Also, there is no stun in the spell anymore. The lowest level spell that stuns is Contagion, and it does one target. Which isn’t all the spell does, so I’d be fine with a 4th level spell that stunned, but not if it also does anything else.
However, looking at stun, the monk can stun up to 4 creatures in a turn at fifth level. By the time a wizard has 4th level spells, the monk is using 5 of 14 ki per day (assuming 2 short rests per day, as the designers do) to flurry and try to stun each target. That’s 4 stuns and 4d6+3(at least) damage.
Comparing what two characters do with their action, im
It also isn’t the effect of protection from energy, it’s comparable instead to absorb elements. Going out of your way to list the higher level spell that does a thing isn’t a good argument.
Not sure where you’re getting alarm, but even if it did have an alarm effect...okay. Alarm is a first level ritual. It’s a ribbon spell.
The point of the spell is that the maze grounds magical energy that is directed into it, and traps the minds of creatures that the caster doesn’t designate as protected by it.
That could be done without the AC bonus, to be fair.
Looking at the comparisons of what a character can do, I’d be fine with dropping the AC bonus, to start with. It’s there to represent the maze protecting people, but the THP is a more normal way to do that.
Having both the damage mitigation and THP refresh on a reaction was my co-dm’s idea, because we want the spell to feel like the energy that gets grounded is then used by the caster. If the spell only did absorption and damage redirection, I’d make it a 2nd or 3rd level spell, depending on the number of damage dice. (generally, spells of a given level are better than upcast spells of a lower level)
But, if it isn’t also a mind trap, it isn’t the spell.
Now, I’m not sold on this, but I may consider making the blindness effect a reaction. Thus, it’s one target per round, and it is a choice between damage mitigation and a mind trap. If I did that, it would be “the target must save blah blah, and until the start of your next turn any target who does XYZ must save against the same effect”, more or less.
And describe the maze as reorienting itself when you use either reaction, like it’s setting itself toeither trap minds or ground and absorb energy.
Or, the spell could gain a longer casting time. I don’t like long casting time battle magic, however. It’s...weird, mechanically and in terms of gameplay.