While this won't allow you to cheat out too many hard hitters, you should be able to secure some great defenders or creatures that are costly thanks to their abilities
The order in this set is WB, BG, GU, UW, RW, RB, UB, UR, RG, GW
Heres the link to make your own tier list: This is my personal tier list (I excluded trainers and energies)
3-Prize Risk : High HP Megas force opponent caution
Some good options are: Meteor Golem, to get rid of problem permanents Stratus Dancer, to counter spells Village Elder, to save your commander Soul of New Phyrexia, to save your board Platinum Angel or Platinum Emperion, when things look dire Some of these options sit quite high on the mana curve
Isshin, Two Heavens as One's ability affects only triggered abilities with conditions that are directly related to attacking, such as "whenever [this creature] attacks" or "whenever you attack with one or more creatures." It does not affect triggered abilities with other trigger conditions, such as "whenever [this creature] becomes tapped." Isshin's effect doesn't copy the triggered ability