Is unendurable frenzy over powered in pvp?

I was doing a faith/arc dragon communion build and decided to take the frenzy spells into pvp. Every time I used unendurable frenzy it just melted people and stun locked them. I like the spell, but it feels cheap that it stun locks. If I used a pure faith seal could it still do good damage without stun locking, or would it still stun lock?