Part of a cycle with Celestial Horseman, Aethereal Horseman, Spectral Horseman, and Ardent Horseman.

Rather than flying wouldn't it make more sense to use Horsemanship from Portal Three Kingdoms ? if only for Flavour.

I did consider that, but these and the planeswalkers are roughly envisioned as being part of a core set, with these being my "titans." I'm not sure horsemanship has a place there, unless I used it as my returning mechanic.

You know, in theory Green has access to Vigilance. On very rare Occasions, it has also used Haste. Haste, with your triggered ability, though, might be too good.

But the white horseman already has vigilance, and fist strike and lifelink would be useless most of the time for it. Also, the red Horseman has haste, and though it could do well with First Strike, I think haste would be too good here.

Shroud and protection don't go together very well though. Protection already prevents a lot of targeting, and protection from two colours is plenty enough "leave me alone" without adding shroud as well. A white or red deck with lots of targeted removal is going to feel like this had protection from all colours, not just blue and black.

Green cards in a cycle so often end up with trample...