Kayn: Increasing gameplay variety between Rhaast and Shadow Assassin

Hello, everyone. As an avid Kayn player, I can safely say the most unique and interesting part of the champion is his dual form mechanic. However, I feel Kayn's current kit misses many opportunities of highlighting the differences between the two forms.

Let's have a look, for example, at Q - Reaping Slash and E - Shadow Step. Now, Kayn's W and R gain additional effects based on the form you choose, while Q gains an additional effect only for Rhaast and E gains an additional effect only for S.A. But why should we stop there? I am sure the reason behind this is that adding additional effects to everything would be problematic balance-wise, but there must be a way to retain more variety in a flavourful and balanced way; one such way could be siphoning power from other skills.

Here are some ideas I had, just to set an example; S.A.'s Q - cast time and animation are moderately faster. Rhaast's E - now heals regardless of entering a wall or not.

On the other hand, it could also be beneficial to switch to a completely different approach altogether: for example, Rhaast's W could hit in a shorter but far wider angle, kind of like a shorter Cho'Gath W. Shadow Assassin's Q might hold 2 charges, and so on.

Another important thing to be discussed when taking into consideration Kayn's transformation mechanics is that it feels... weird. I, for one, would suggest to set his transformation to be automatic once reaching level 10, but reducing this requirement by the amount of orbs collected, down to a minimum of Level 6 transformation at its earliest.

How would you react if changes like this were to go live? Would you see it simply as an unnecessary buff, even if other skills such as W and R were nerfed slightly to compensate?