I feel like the whole concept of Inspiration tree is to give more freedom to the player, and Let new play-styles to be created.
Although at the moment it is mostly just "extremely situational" runes.
So here are two original ideas That I think will open dozens of ways to play any champion, but will be too much for the balance team to handle
1. **Rune Master**
_If you pick Rune Master as your Keystone you will be able to pick any 5 minor runes, from multiple trees, and even parallels triplets._
(+Bonus % effect to the runes if its ends up too weak)
2. **Adaptive Warrior**
_If you pick Adaptive Warrior as your Keystone, All the damage items will grant and stacked with 'adaptive force' instead of AD or AP._
(I think it would also be cool if it make your Abilities proc on-hit effects, but that can be WAY TOO MUCH OP)
If you liked the idea, let me know In comments how you would use it
That's all for now,
and have a nice day