Some things I would look into:
Attack speed: archers, dragons
Range: blizz, runes
Powerbuilding and repairing: players do it like it's free
Bloodlust at x1.5: as long as it keeps that "here come the ogres straight at you destroying everything" effect.
Modifying or replacing ranger upgrades: they're good ideas but not useful.
Ed said its already possible to set a specific amount of damage from bloodlusted units to 2x... he also said that it can be as low as x1.5 and even as big as 4x !!
But even if this spell is set up to only deal x1.5 damage, you could imagine the amount of people that would complain about it.
There's some feature in Ed mods already to allow "auto-healing" from paladins, as long as they have mana to use the spell but its still not enough..
I already gave some re-balance ideas on here:
https://forum.war2.ru/index.php?topic=7200.msg102081#msg102081I also thought in increasing bloodlust mana cost from 50 to like 75 or 80. Even without changing bloodlust damage, I think 50 is way too low..
Ogre-magi pop out with 85 mana already. You use bloodlust one time, and when runs out you're ready to cast it once again to deal insane additional damage.
In case would be 75 mana, i also would like to set up Runes mana cost from 200 to like 150. This spell is fair enough to have less mana cost but I think would be way more fun to see Ogre-magi using all of its spells, including runes.