Players' Pokemon TCG tournament collections that included either of these cards were able to cause a control and lock strategy which did not balance well in games
Special illustration cards seem to replace one of the two reverse-foil cards rather than the rare or holo-rare slot, so you could get lucky and get a special illustration Pokmon ex and a full art Pokmon ex in a single pack (I think?), but the odds would be pretty small, and thats only because the special illustration card replaces a different foil-style card of the 3 foil-style cards
Typically they're the cards that have the strongest synergies among the entire deck and really encapsulate what the deck wants to accomplish, potentially even more so than the commander
But Charizard achieved 123 PSA 10s from 4,034 submissions, a 3% hit rate nearly three times higher than Lugia's
You can build around it however you want, though Ramos specifically incentivizes multi-colored cards
This is mainly because the most it could do was provide backup stun and was fully outclassed by something like Trunade who was for a time at 2-3, and this was at the time VERY outdone by Heavy which directly got rid of the problem