You are never forced to activate mana abilities to pay costs, so if there is a mandatory additional mana cost (such as from Thalia, Guardian of Thraben), you can decline to activate mana abilities to pay for it and hence fail to cast the suspended card, leaving it in exile
Creatures in general are must-answer problems, and so the threat level of you dropping a Voltron attacker that you might have protection for later just doesnt register anymore
Pity that when it actually released, none of it had democracy/anarchy voting to reference TPP
There were also other Japanese exclusive MOM tokens that are on the secondary market, with most valued at around $30 or less
As for the card itself, Najeela, the Blade-Blossom is fairly popular in Commander, and a real star in cEDH
For instance, you can use the grass effect in the Nature category for your grass type Pokemon cards