I have a couple problems here
the shadowrath
the shadowrath unit is a melee unit ONLY, the unit shouldnt have a ranged advantage, otherwise their true main foes (the albowtross and archidon mass) would stand no chance against the new ranged weapon, shadowrath would have to have its price increased completely in order for this to take effect. however im good with shadow mastery, it doesn't change much except now when you go shinobi the enemy doesn't notice it, but make it so the shadowrath dont say shinobi when this is upgraded, so the enemy doesn't hear you as well.
The meric
worst combat unit in the game, and it must stay that way. the magical portable healer shouldn't be casting spells, that's the magikills job. So I say don't freaking take somebodies job god damnit, its not nice.
the crawler
these speedy little fucks need those upgrades reduced otherwise the help you o so need aint gonna come. they are obsolete when it comes to upgrades, so reduce em.
the archidon
I absolutely love the archidon, they are considered my second best unit. but teleportation is going a bit to far, WE HAVEN'T EVEN MADE THAT TYPE OF TECHNOLOGY YET, and archidons aren't magical nor are they sneaky enough to move like that, keep the flame arrows, but lose the teleportation (why teleport when you can use those legs of yours).
the medusa
this unit already can kill a unit instantly, why give it an ability so it can just kill other units instantly faster. two blocks of freaking health lost on the single unit it hits, it will be finished with the spearton in only 3-4 shots, not including the venom flux sent out to the other enemies, reduce the damage done with this upgrade or make it toggled and cost 50-75 mana
i had my own upgrade ideas but i think they are a bit OP
THE MARROWKAI
small minions, give the marrowkai the ability to spawn small little demons that have a 50-50 chance to be either holding a bow or a sword, this costs no mana or population to use, but it has an insanely long recharge time (80-90 perhaps, so players dont get OP with this), these units do less damage than a swordwrath and die instantly from a single miner attack, but they are free of charge, almost as fast as a shadowrath (a shadowrath can catch up to one of these but no other unit can), controllable, you start with this upgrade, and a farm of these units can be started but its not recommended
THE MEDUSA
darkness, medusa shoots a ball of darkness at a single enemy that does as much damage as an archidons arrow, costs no mana to use and medusa starts with this. has a recharge time of 3 seconds
THE JUGGERKNIGHT
anger mismanagement, the Juggerknights anger grows more and more every day, every kill he makes stacks up little by little (can stack damage up 10 times, only one juggerknight can take the stack, so if 2 juggerknights are attacking a single swordwrath whoever got the last hit gets the stack), each kill gives the Juggerknights damage an extra .1 damage all the way to 1 full extra damage, this upgrade costs 150 gold and 150 mana with a time of 50, HOWEVER when its toggled the juggerknights health does not regenerate over time even when garrisoned, when toggled off the whole damage stacked disappears and he can start regenerating again
anger mismanagement 2, the Juggerknight can now stack the damage up 20 times, allowing him to get 2 full extra damage, however once you pass the tenth stack, you will start slowly losing health as if your regeneration was going backwards even when garrisoned, when turned off you lose the damage stacked and begin regenerating again, this costs 400 gold and 150 mana (this gives the juggerknight 2 toggled abilities, so you can choose whether you get to continue going with the damage stack)
THE SPEARTON
honor, the Spearton when dies now throws the spear as a last attack, instantly killing ONE of the weak foes, he will always target the strongest of the weakest (heres a list of the order he will target in: albowtross, wingadon, meric, archidon, swordwrath, miner from either side, crawler, and bomber. he targets from the most expensive to the least expensive, most expensive always is targeted first unless blocked by something like a giant), if their is no weak unit to instantly kill on the battle field, he will just randomly target one of the truly strong units, of course not instantly killing them but damaging them a little. costs 250 gold and 50 mana to research with a research time of 60
shield stab, the spearton takes out the spear while in shield wall and can now stab units as its holding the wall, this does the a bit less damage than its regular attack but does not stun, it costs no mana to use and has a recharge time of 7, this ability costs 300 gold and 100 mana to buy with a research time of 20
shield bash 2, the speartons bash now hits 2 enemies, it costs 100 gold and 100 gold with a research time of 30
THE ALBOWTROSS
better flight, the albowtross is a bit faster, costs 200 gold and 50 mana
THE MAGIKILL
magical range, increases the spell range of all spells, some spells can even be fired off screen, this costs 250 gold and 600 mana with a research time of 35
magical shield, spawns a small shield around the magikill that phases a single attack once, after that single use the magikill is vulnerable and can be harmed, this ability comes with the magikill and is a single use ability (you start with it, but it cant be casted by the magikill)
THE MINER FOR BOTH SIDES
double tap, the gold is now doubled to 150 and the mana gained is doubled to 14 per person, this costs 600 gold and 500 mana. the gold increased does not increase the amount of time it takes to mine a full bag of gold but it does increase the amount of gold taken from an ore