With Zevlor, that simply wont be the case
It will include the same standard text, allowing the player to draw a random Basic Pokemon from the deck, but with new golden artwork and a border
The cost comes right before a dash - and every part of the cost must be paid to use it
All of this is to say that Oko is extremely hard to answer in combat, so it largely requires a spell to deal with it (or, as we see in Throne of Eldraine Standard, you can go way over the top of its threat generation by, for example, making lots of 2/2s with Field of the Dead)
Most of the most valuable Pokmon cards ever printed are Pikachu cards, and even modern Pikachu cards can go for hundreds or even thousands of dollars
To beat Yasharn, you need things that will remove a four-mana 4/4, which is easier said than done