I take it, like everything else, Opportunist has to follow the "rule of 3"? the card allows up to 5 tokens on it and there is no mention of the "rule of 3" but I presume it has to follow it....yes?

And thanks for helping!

Opportunist actually adds to the die roll, because of that it is not subject to the rule of 3

Ex: Bullseye with an 11 attack and 5 opportunist tokens takes a shot at KC flash. Needs a 9. But rolls a 4. He can burn all 5 tokens to make that hit and its now like he rolled a 9.

to expand rule of 3 is in regards to combat values.
dice roll is not a combat value.

Opportunist was specifically worded to avoid the rule of three.