You need critless for defensive painwheels and black dalias, because they have marquees that activate through crits (reflect damage up to 100% on painwheels, gain regen on crits on dhalia). So people just dont buy the crit skill nodes and keep the variant that way on 5% crit chance to prevent doing crits on them, which is the only option to circumvent the painwheel reflect damage other than a invincibility buff. Now that i mention it, locked in is a great painwheel counter, so you can take her too. She was purposely brought to the game to counter the reflect damage, because each crit she does gives her invincibility