Does this scenario include Tengu being female (assumptions of a female tengu in casual thread)? If Tengu was a male, then I think Phase 4 would be more popular. If it was a female tengu, then I'm not sure.
Free Step Dodge
JKT
Kronin
If I have to compare DoA4's Tengu with Phase-4, very likely would win Phase-4: a cool loking fighting style (teleport moves are always a guarantee), the DoA fanservice toward the female characters, the charm of the nostalgic effect of Kasumi Alpha from DoA2.
Kronin
By the way I'm sure that TN would be able to make of Tengu Bankotsubo a cool looking and effective character for DoA5. So if his new version was released at the same time, wouldn't be a so easy matter to predict the most popular.