I'll be honest -- until now, whenever that text appeared, I had no idea what it even meant. So I'm loathe to offer suggestions, but all this talk of active abilities and the like doesn't really feel inherent, ie something that just 'happens.'
My first thought would be to build opportunity a little faster, then automatically trigger it on next attack, alternating between the two effects, applying a nice group buff within a reasonable range. Or have some buffs to your allies and some debuffs to your enemies, depending on opportunity type. For example, it might apply a nice restore/resist bonus to nearby allies while applying a reasonable-magnitude stun or disorient or -recharge/-speed debuff to your target and all enemies near your target (or targets, if the triggering ability is an aoe).