Various concepts for Keystones and Support Gems

These really could be either keystones or support gems, possibly both. But I will list what I think it should be put as. Also I criticize my ideas, they are not perfect and some could turn game balance upside down. I don't ask for these ideas to be implemented word for word, just feeding the fish so to speak. I remember the devs saying Magic The Gathering is a big inspiration for skill design in this game (or at least the rather direct but still labrynthine descriptions).

KS* Charmed Spirits: disable energy shield cooldown regeneration, apply an ES boost on any skill scaling with total skill cost + intelligence flat mana bonus.
; I'm kind of curious if the other stats will directly scale with certain effects. I don't really have any opinion on this other than stat scaling keystones are already scrutinized mechanically.

KS* Possessed Armor: Physical Damage reduced by armor and blocks applies as lifesteal regeneration to player. Damage over Time effects hurting the player instead apply all their remaining damage instantly once the player moves.
; You could theoretically make a CI armor/ES ghost reaver build to take full advantage of this. Not intended specifically for said build though. This could be a fun mechanic if not the easiest to balance and I'm willing to throw borderline poverty amounts of money at it.

SG* Disruptor Touch: Reduce armor on melee hit to self and enemy based on current Energy Shield.
;I like to think this is balanced well to be useful even for pure ES builds despite the dangers of being able to get one shotted by any physical damage. The length of the effect is as long as elemental proliferation, and it doesn't stack. Should last long enough to allow slow weapon usage at early levels, and enough time to escape in case youre debuffed and realize a high phys mob is wandering towards you now.

KS* Rimeblood: Frost skills have a chance to replicate the skill effect to a random nearby enemy. You can't freeze enemies anymore.
;This could become very dangerous as new skills are revealed. I feel it could be balanced now though.

KS* Forged in his Holiness: Armor applies to all fire damage rolls inflicted from or on player, on top of fire resistance. Fire damage spells and attacks inherit strength physical damage value.
;It can be catastrophic to take on characters without armor. Most of all it matches the flavor of iron will. This may strengthen templar/marauder casters too much though. Consider how armor scales though and you can get increasing returns theoretically.

KS* Arcane Assault: Stun rolls inflict lightning status effect instead of stun. Affected by stun threshold but not affected by stun length.
;So you get to deal more damage, but it's also extremely dangerous if you're solo and you need a stun for crowd control. Also it doesn't really synergize with lightning users well if they can get their stacks up. Meanwhile nobody else ever built lightning damage ever again... not a good outcome.

KS* Grim Inspiration: Totems regenerate with your health regeneration stats when you have low health. You do not receive said effects during low health.
;Because why the hell not lol. This is probably the easiest one to transition into current gameplay balance. Support gem form could replace the penalty with high mana cost.

SG* Deathly Harmony: Auras consume health AND mana per second (at equal rates splitting the cost) instead of reserving. Bloodmagic would convert mana cost back into health cost for this keystone's effect. Health scaling damage done to facilitate cost is chaos damage. Auras have (almost) no cooldown. If your mana pool empties the auras are turned off.
;I have no idea how balanced this is, probably not very. You could possibly equip every aura in the game but I don't really know of a build that could take advantage of that. From then on there though something OP would come of it unless auras were meticulously balanced. I think thats too much effort to change whole game possibly for this. Very odd support gem in a nutshell.

SG* Cursed Banner: Minions will turn into their own corpses if not killed by Freeze or Explosion. Any curses casted apply to your minions directly to their disbenefit.
;Intended for lower mana summoner builds. You will use curses less possibly but you can maintain zombies even easier, or you can use corpse explosion instead anyways if you so choose.

KS* Illusionist: Successful evasion rolls increase movement speed attack speed and cast speed. Stun length is increased when hit.
; I figured this could be usable on melee even, but it makes mobs dangerous. Sounds like a PvP killer though.

SG* Macabre Perfection: Failed enemy evasion rolls can increase critical multiplier for the hit. Reduced attack speed.
;This should scale with how your gear can roll for multiplier and the actual crit chance effect even. If your critical would still "miss" this would not change anything. Would also add some new scaling to accuracy.

KS* Blackened Steel: Recieving Burning/Fire Damage gives you lowered cold resistances and increased fire resistances. Vice Versa.
;Additional Maximum Fire/Cold Resists exist behind it possibly. Might be better as a unique but bring back Avatar of Fire anyways lol.

KS* True Brawler: You have no accuracy for weapons. Every attack is a critical.
;Time to get those Facebreakers back on for Merciless. A fun addition more than anything. Probably won't make it in anyways B) but think of all the facebreakerless clones too... please do this on April Fools at least, possibly as a support gem reward for a possible race on that day...

KS* Exorcism: When you apply a critical you deal fire damage to yourself and to enemies based on noncrit fire damage of the spell or attack.
;Added as an afterthought as an intermediary keystone to accessing "Forged in his Holiness". Made to increase investment for noncrit builds mostly but useful and dangerous for low armor builds as well. Could be used well with elemental tank builds as well.

I wrote this awhile ago but I went back and added some more ideas and notes below every concept. Feel free to roast, I just wanted to write this out for the hell of it.

Posting skills as I'm playing medianxl ultimative right now so you might notice some parallels
*SG* Banewolf (Support gem minion state): Dex summon that you can attach to curses. It will proc the curse whenever it attacks. Single target only (get more wolves to spread curses faster).

Golem (Support Gem minion state): Str summon that you can attach to melee skills. 60 reduced attack speed.

Shadow Blade(melee attack; daggers,swords,axes): Level 31 Dex/Int gem. 110 effectiveness. Half physical damage dealt as cold damage. Damage chains to a local enemy near the first hit. Chain damage is all cold conversion with 75 percent damage effectiveness. Can use chain support gem. increased ailment lengths on your attack.

Entropy Shield(Shield buff): Level 31 Int gem. If an enemy you block has viper stacks on them, the viper stacks are detonated for flat chaos damage in an area. Damage scales with amount of viper stacks. Has 50 damage effectiveness.

Dust Vessels(Minion Summon): Level 31 Int gem Spawns armored minions in random positions around caster. Minions suffer burn damage permanently once its procced on them but deal bonus fire damage when they are burning. They have bonus armor that can be increased by determination.

Nova Shot (Arrow Skill): Classic medianxl skill level 24 Dex skill. Shoots arrows in random directions around player over time. +1 projectile every 3 levels. 65 damage effectiveness. Faster attack speeds increase the rate of arrows and skill animation like cyclone.

Storm Totem (Spell Totem): Uses a projectile similar to ice spear but without pierce. Slow fire rate but shoots 3 lightning spell projectiles in succession. 120 damage effectiveness.

Hurricane Totem (Spell Totem): Cold spell totem with a combination of arctic breath and firestorm mechanics. Half rate of firestorm with ice chunks that also create frozen ground at 60 percent aoe of arctic breath. 40 damage effectiveness.

Sundering (Support gem for melee/ranged attacks): decreases armor by a percentage (not physical resistance).

Stand Your Ground (reserve buff): While active, standing still will slowly regenerate endurance charges at about 1/14 seconds at first skill level. Slows down movement speed as well.

Health (Aura): Level 31 Dex Aura that increases chaos resistances from 3 percent to 14 percent. High flat mana cost (as much as clarity and scales as high).

Homing (Support Gem): causes projectiles to redirect to nearby enemies with precision after travelling. The distance that the projectile travels before becoming homing is very short but can be improved by projectile speed. Superceded by pierce and chain. Homing gem itself decreases projectile speed hence the short activation range.

Bloodlust (Aura): Adds LGoH as an aura. Nowhere near as efficient as the support gem version.

Spell Shield (Support Gem): attach to a spell to proc it on blocks. 220 mana cost increase.

Feeling in a trap mood today.

Earthquake trap: Level 24 Dex skill targets enemies in succession while it remains alive, causing repetitive knockback in a small area.

Lightray Trap: Level 31 Int skill uses version of vaal laser with shorter range. Potent base lightning damage.

Deathgrip Trap: Level 24 Int/Dex skill with strong chaos damage and chance to critical. Does moderately high damage to a single target with a higher critical multiplier.

Cluster Mine: Level 24 Int/Fire skill with delayed fire damage component. Mine splits into 3 AOE projectiles when detonated that target closest enemies.

Gate Mine: Level 24 Int skill with small AOE effect, teleporting enemies to your position.

*SG* Compact Traps: Level 24 Dex support gem Increases reserve trap amount of skill. 150% mana cost increase.

*SG* Heavy Mine: Level 31 Str support gem Increases AOE and Damage of skill. When you deploy a heavy mine it is the only mine that can exist from the player, using other mines will remove the heavy mine. 170% mana cost increase.

*SG* Networked Mines: Level 31 Int support gem reduces mana cost of Mine depending on how many of your mines you are nearby (uses standard mine AOE to determine aura effect size)

Will update with more trap and mine related skills.

If you are wondering I do come up with these concepts out of fun and boredom. I do not claim to be a master of game balance.