I don't get this mentality. The PCs are meant to succeed and to use their abilities. CELEBRATE IT. Don't shame it. Don't try to beat it down - only counteract it if an NPC/monster has reason to know of it and counteract it. If they use it in 90% of their battles - great! Does Spider-man need to be stopped from wall crawling or using his webs? If they want to mix things up, they can. They're the heroes.
You're not trying to beat them. You don't need them fearing death in every combat. Some combats should have no fear of death - but fear that something else will go wrong, like a prisoner being killed, an enemy raising an alarm, a ritual being completed, people you're protecting being attacked, etc...
So my answer: Just play the game and celebrate their success. Every time I've seen a DM really embrace this mentality, the quality of their games (and the enjoyment of their players) has skyrocketed.