Lesser Flight should be defined as the following:
Ability to:
1) traverse impassable tiles (Void)
2) traverse difficult terrain at a rate of 1 AP (Sea, Mountain, Crate Field)
3) avoid grounded terrain damage (Lava, Hallowed Ground, Chain Death)
4) seep through doors
5) the ability to attack Flying characters with close combat attacks
Compared to true Flight, it would have the following downsides:
1) No ability to avoid pet/close combat attacks
2) No AP discount by default
The following skills would be defined as providing Lesser Flight:
1) Levitate spell
2) Cloak of Ineffable Mystery and children
3) Wisp Form
4) Shadow of the Bat
5) Ghostwalk
The following skills would enhance Lesser Flight in the following ways:
1) Cloak of the Ineffable Breeze and Wisp Form replaces AP cost with MP cost while MP lasts
2) Shadow of the Bat and Ghostwalk halve the AP cost of movement
This suggestion has been made for the reason that some forms of Lesser Flight (Ineffable, Levitation) really do not help in Purgatorio. It should be good enough to get you over Void tiles. It's very disappointing that it does not. Not providing free shots against outdoor pets or an AP discount is already a big downside compared to Flight.
Also for increased clarity, this gameplay term should provide consistent bonuses to all skills that have it. Like in a card game, a shared term should do the same thing for all cards that have it.
If I understand correctly, this suggestion would enhance Shadow of the Bat and Ghostwalk with seeping through doors and Cloak of Ineffable Mystery and Levitate with the ability to traverse Void. I think these buffs are thematically consistent: Ghosts can go through doors, Bats are small and can find a way around doors and Levitating provides altitude control in games like Morrowind and is used in that game to reach the upper heights of the mushroom towers built by wizards, it would serve equally well to travel between floating islands.