Although Okidogi is a Fighting-type card and Munkidori and Fezandipiti are Psychic, all these abilities require having a Dark Energy attached to work
That has nice implications in affinity decks, allowing you to send a Myr Enforcer at your opponents face for 9 damage, or something along those lines
However, unlike investigation, where it was common to reduce difficulty with a flashlight and a bunch of old keys, combat/evasion to reduce difficulty is a somewhat unfamiliar concept, there are not enough cards to link with, and combat cannot consider whether to use it or not depending on the situation like an investigation, so unlike Shine a Clue, the evaluation is not so good
It only needs one Six Samurai Monster and another Warrior Monster to make, something Six Samurai decks have no issue in doing
People love +1/+1 counters in EDH, but this card barely sees any play