Most of the legends matter stuff is on a handful of underperforming rares though (i.e., Clive's Hideaway, Serah Farron), so dont expect to build around legends specifically
You need to gather your power before commencing that all-out attack, so if your opponent can prevent you from getting board control early on, youll get crushed before you can get your vampires ready for war
The rate isn't bad for what you get, either, and the Great Train Heist will be useful at every stage of a game, whether you're using it for an early mana advantage, as a combat trick (offensively or defensively), or as a source of extra damage to close out a game
The best fit depends on your risk tolerance and your schedule
Yuriko, the Tiger's ShadowYuriko, the Tiger's Shadow's Ninjas makes for a good home, because you're spending mana on your turn to activate ninjutsu abilities
The creature itself gives you a free +1/+1 counter on your end step, making a creature you control slightly larger