reflect damage support and thorns aura

The ratio of monster damage to life in most ARPGs is extremely different from the ratio of player damage to life. This is mostly done to keep the numbers from getting out of hand and to keep the combat engaging, but it means that any form of direct proportionate damage reflection is extremely ineffective against monsters and laughably ineffective for bosses.

The exact DPS numbers for viability is very much a subjective thing, but for argument's sake (and to make the math easier) let's say you wanted to hit one million DPS for your build to feel like it did enough damage to be playable in red maps. That means you have to be able to do one million reflected damage per second, per enemy. Even if the skill had ten thousand percent damage effectiveness (which it absolutely couldn't, because then any flat added damage would completely break the game), that still requires your build to be able to survive taking 10,000 damage per second, per enemy, after all sources of mitigation are applied because the damage absorbed by your defenses would not be reflected.

And even if this were somehow possible to survive (it's not, because that 10k damage you have to take per second is still per enemy which means absolutely any pack of monsters would gib you), you still run into insurmountable issues when you get to endgame bosses. Example: the Shaper's frostbolts do about 7000 base damage each. Even at this unreasonable ten thousand percent damage effectiveness, and assuming you have zero cold resistance, you're only reflecting 700k damage back each time you're hit, which is then mitigated by his resistances. It would take somewhere between 100 and 200 of these reflected frostbolts to kill him... easily a 15-20 minute fight. Not that you'd be able to live that long in an area rapidly filling with void anomalies on a build with zero cold resistance.

This is why POE abandoned that concept entirely in favor of Reckoning, Riposte, and Vengeance. Because those gems use your equipped weapon(s) and scale damage/crit chance/etc as if they were regular melee attack skills, they can actually be scaled to reasonable amounts of damage without requiring the player to sacrifice all of their defenses and run zero-resist builds. The last time I played this I used Facebreaker and I got both Reckoning and Riposte to over a million damage per hit, each, both of which could trigger more than once per second, on an incredibly tanky build with 80% block/spellblock.

So, to go all the way back to the beginning: the thing you want is in the game, but better.