For Easy and Normal, at least, the optimal route for the WE5T0NE category SEEMS to be:

1. Human Unknown. Transform to Mouse back in town.
2. Mouse Unknown. Transform to Hawk back in town.
3. Fly to shop and buy ~25 Thunder spells (maybe Medicine for safety).
4. Fly to Lizard Unknown. Transform to Lizard before dropping below Fire Ant-Lion.
5. Lizard Unknown. Equip Magical Sabre for last room only (to not break blocks). Remember to switch back to Legendary/ Tasmanian so you don't deal 0 damage. Transform to Hawk when back on land.
6. Fly to Hawk Unknown and complete.
7. Take return door in Magical Sabre room as Hawk. 8 ) Fly over town and out to the screen above Lion's Unknown.
8. Transform to Lion and do Unknown.
9. Transform to Piranha when back in ocean. Swim as much as possible to Piranha Unknown and complete.
10. Transform to Human back in town. Fight Captain Dragon.
11. Fight Mummy and Zombie Dragons as Lion in any order.
12. Fight Daimyo Dragon as Lion.
13. Fly up to door to Vampier Dragon (go left around the walkway).
14. Fight Vampier as either Human or Lion with Legendary Sword.

Always make sure to equip the Legendary Sword before fighting any enemies, as it's about twice as powerful as the Tasmanian Sword. It's likely fastest in Lizard's Unknown to equip the Tasmanian Sword after collecting the Stone and trying to avoid enemies (save a menu).

Any thoughts or improvements to the route are welcome, as are questions and discussion!