The bottom compartment will fit the remaining tokens from the Premium set (+ space for more): 16x Keyword tokens Reckless, Cant Quest, Evasive, Cant Challenge, Cant Ready, Support, Rush, Bodyguard, Ward, Challenger +1, Challenger +2, Challenger +3, Challenger +4, Resist +1, Resist +2, Resist +3
However, it's quite heavy, so realistically you'll often use it for around 3 mana
It can also take down a Garchomp C if you have an Expert Belt () Finally, Regigigas Lv.X is a powerhouse attacker that is both intimidating and disruptive
In most cases it is better to continue playing to call their bluff because, if your opponent doesnt have a way to destroy Roots of Yggdrasil you can at least progress the game