Honestly, i think Magery/Necro summons need to be buffed to compete with Mysticism summons. Currently Magery summons such as BS, EV, Daemon, and Elementals don't even scale with Magery/Eval skill. All pictures were taken with max relevant skills, and Lvl 3 Mastery (+15% HP and SR).
BS used to be nasty, able to inflict Greater Poison. At least make BS a fast cast (1.5 secs instead of 4.5) and 1 Control Slot again. Giving BS GM Wrest/120 Parry (that many rotating blades should be able to easily parry most incoming attacks) and maybe even Grasping Claw (lowers Physical Resist) or Repel would be interesting (they'd need Mana to use these).
EVs used to be able to inflict Curse+Mana Drain+DP with their hit. Conductive Blast would be an interesting addition to them (would also need Mana).
The Daemon/Elemental Summons suck right now. The Daemon could provide a SDI buff while active (continuously lose Karma while maintaining a Daemon summon however, a demonic bargain in exchange for power), or have it's stats buffed and go back to a 5 slot with a longer cast time (making the Daemon Magery's "Big Boy Summon"). Make having an Elemental out give you a corresponding Damage Eater/Resonance buff, while buffing their stats.
Wouldn't let me lore a Revenant (since they're classified as human NPC), but even with 120 Necro/120 SS, they're a total joke. They get their ass whooped so hard by even a Boura. Give Revenants the ability to apply Curse with their hit (or Spellbinder debuff casting), and the ability to allow their summoner to Track the target (arrow on screen).
Necro Familiars mostly suck too, and don't scale with Necromancy/SS skill. Allow Familiar skills to scale with Necro/SS skill, up to 120 in all their skills at 120/120 Necro/SS. The Death Adder should give passive Poison Resistance (similar to Orange Petals/Vamp Form) to it's summoner, and Vampire Bats should give +10% Life Drain to all attacks/spells for it's summoner.
Here's Nature's Fury, Pixies, Imps, and Reaper at 120 SW/Lvl 6 Focus. The Nature's Fury is a decent Physical tank, the Pixies are decent for interrupting enemy spellcasters, and the Imps are useless. The Reaper is formidable and useful, he actually has AoE capability and can tank to an extent (especially with how he pulls enemies to him). Arcane Empowerment can increase summon HP by 10%.
Here's Animated Weapon at 120 Mysticism/120 Focus/120 Tactics/120 Anatomy. The AW inherits 50% of your Tactics/Anatomy skill as it's own. Honestly, not worth the skill point investment to max it out. Would be better if it got Armor Ignore (needs Mana).
Now here's the Reigning King of Summons. A RC at 120 Mysticism/120 Focus. These things are incredibly powerful, easily able to solo a High Plains Boura where all other summons failed.