Regarding Mountain drake
Mountain drake is sometimes game changer, but also a lot of time kind of irrelevant, especially when behind.
What if Ocean drake was split into 2 drakes, one for mana regen (named Ocean drake) and one for health regen (named mountain drake)
My proposed dhangelist :
Ocean drake :
Restore 4 / 8 / 12% of missing health and missing mana every 5 seconds while out of combat from enemy champion.
Restore 6 / 12 / 16% of missing mana/energy every 5 seconds while out of combat from enemy champion.
Mountain drake :
Grants +10 / 20 / 30% bonus true damage to epic monsters and turrets.
Restore 6 / 12 / 16% of missing health every 5 seconds while out of combat from enemy champion.
Also, for a more comprehensive understanding of why mountain drake current buff is problematic : https://boards.na.leagueoflegends.com/en/c/gameplay-balance/9YymesJl-one-of-the-main-offender-of-baron-nashor-rush-strategy