It should be better to make targets from this become snowmen http://newsoflegends-content.s3-website-us-east-1.amazonaws.com/2015/11/Snow-Bard-R-2.jpg
And for other skins, make his Ulti relate to the theme.
The reason his ult has stuck with the zhonya effect is because it has to be have clarity that it is a Bard ultimate that makes all in the ring invulnerable for that time. If different skins had ults that reflected the theme (like roots for elderwood Bard ult) it could confuse a lot of players. Some allies might think it is a Zyra ult, for instance, which would cause allies to blow their spells on the enemy which would be bad
For Elderwood Bard we could have roots sprout up and root targets hit.
For Bard Bard... We have nothing actually.
