Mana produced by Somberwald Sage can't be spent on activated abilities, even ones that put a creature card directly onto the battlefield, such as unearth or ninjutsu
Other Pokemon TCG expansions are vaguely based on the main series games, and thus the settings and backgrounds of the cards are in fictional places for instance, Astral Radiance is set in Legends: Arceus Hisui
Heres my submission: This Unlimited Neo Discovery Tyranitar is from my childhood
[L][L][C] Electric Ball: 130 damage
Adventure Lands Ishgard, the Holy See Jidoor, Aristocratic Capital Lindblum, Industrial Regency Zanarkand, Ancient Metropolis Midgar, City of Mako The adventure lands from Final Fantasy provide utility in specific decks, with the upside of a land drop after the adventure
If you have the extra budget for it, you can also run a Sneak Attack style deck to cheat Slivers into play