What I did is:
Albinauric Ashes: Now summons 2 Bloodbane Albinaurics 
Ancestral Follower: Now summons 2 putrid variants of ancestral followers (cut content). Yes, they inflict rot to enemies
Ancient Dragon Knight Kristoff: Added a Halightree Knight 
Archer Ashes: Now summon a giant albinauric crab (inflict sleep to enemies)
Avionette Soldier: Now summons Magma Wyrn
Azula Beastman: Now summons 2 Ancient Heroes of Zamor 
Banished Knight Engvall: Now summons the tree variants of babished knight who teleport (dual sword, halberd and shield), because why not?
Banished Knight Oleg: Now summons Crucible Knight Ordovis (sword and shield), Crubible Knight Siluria (Spear) and Tanith's Knight
Battlemage Hugues: Added Lazuli Glintstone Sorcerer (the one with sword and shield) Ancient Dragon Knight Kristoff 
Black Knife Tiche: Now summons Alecto and Melina
Blackflame Monk: Added Godskin Apostole
Bloodhound Knight Floh: Added Blaidd alongside Floh (just for lore) 
Clayman Ashes: Now summons 2 variants of Abductor Virgin
Cleanrot Knight Finlay: Now summons the 2 variants of this girl
Crystalian: Now summons the 3 putrid variations (ringblade, spear and staff)
Demi-Human: Add 1 Chief variant and Demi-Human Swordman Yosh (DLC summon) 
Depravedd Perfumed: Now summons the Baleful shadow (hungry Blaidd)
Dung Eater: Added a Royal Revenant (Just for add a equal disgusting character with the Dung Eater)
Fanged Imps: Now summons Blaidd and Melina Duelists with 2 hammer and Putrid Duelist with an axe
Fire Monk Ashes: Added Fire Knight Hilde (DLC summon) alongside the monk
Glintstone Sorcerer: Now summons Mogh, the Omen (the one in sewers)
Godrick Soldier Ashes: Now summons Divine Bird Warrior Ornis and Horned Warrior (both DLC summons)
Greatshield Soldiers: Now summons 3 Lazuli Glintstone Sorcerer 
Haligtree Solder: Now summons Draconic Tree Sentinel
Kaiden Sellsword: Added 2 variants of exile soldiers
Kindred of Rot: Now summons Margit, the Omen Morgott, the Omen King (the weakest version was, well, too weak. So I decided to bring Morgott here)
Land Squirt: Now summons Tree Sentinel
Leyndell Soldier Ashes: Now summons Black Knight Commander Andreas and Captain Huw (both DLC summons)
Lone Wolf: Now summons Red Wolf of Radagon, Guardian Lion and one of the giants dogs from Caelid
Lhutel the headless: Added 3 mausoleum soldiers (all headless)
Mad Pumpkin Head: Now summons hammer and flail variants
Man-Serpent: Added one with Magma Blade 
Marionette Soldier: Now summon Golem Smith and Bloodfiend Hexer (both DLC)
Mausoleum Soldier: Now summons a an Elite Runbear (the only variant who work so far)
Miranda Sprout: Now summons Erdtree Avatar
Nepheli Loux Puppet: Added a Stormhawk (just for lore)
Noble Sorcerer: Now summons Flame Chariot
Nomad: Now summons a Frenzied Troll
Omenkiller: Added 2 rotten dogs/stays
Oracle Envoy: Now summons Royal Knight Loretta
Page Ashes: Now summons Ancient Dragon Florissax (DLC summon) Removed, she is an NPC, so it doesn't work without DLC (at least not for me). Now summons Curseblade Meera and Gravebird (both DLC)
Perfumer Tricia: Now summons Tricia with Depraved Perfumer Carmaan
Putrid Corpse: Now summons 2 Cemetery Shades
Radahn Soldier: Added Redmane Knight Ogha with them
Redmane Knight Ogha: Added Kristoff and Lhutel alonside Ogha. The best 3 knights of vanilla game's summons
Rotten Stray: Now summons Graften Scion
Skeletal Bandit: Now summons Beast Clergyman (this one was difficult because he just keep falling into the ground. Luckily, a kind soul help me via Reddit)
Soldjars of Fortune: Now summons Alexander (Farum Azula's version) alongside 2 little soldjars 
Stormhawk: Now summons Godfrey (gold phantom version)
Twinsage Sorcerer: Now summons a Carian Troll Knight
Wandering Noble: Now summons Bell Bearing Hunter
Warhawk: Added 1 Stormhawk
Winged Misbegotten: Now summons a Leonine Misbegotten

Update v4:
Added new summons.
Change spirit effect for all summons (except puppets).
Fix damage of some summons being too high, now they should be "normal" for a spirit ashes standards.

V4.2: Now with custom icons!

V4.3: More summons. Fixed several summons being too weak and another ones being too strong. Now all should being "normal"

All summons now have a little regeneration hp.
Added "spirit color" to all summons.

NOTE: Most of the changes is for thous who don't own the DLC (like me) can enjoy, at least a little bit, the new thinks this DLC brings.
Sadly, I can't do anything more than this. I mean, I can't bring an boss or an NPC from the DLC to use them on summons. I just can't, I already try.

Now working on 1.12.3 and 1.12.4 version of the game
You can use this mod and merg it with Unlocked Spirit Ashes
Install: 
Put the regulation.bin in "game" folder of your Elden Ring (backup first) or merg it with Smithbox (I provide the .csv archives)


Big thanks to Omnibuson for let me know about the new tool ^^.