I was thinking about this the other day. Increasing the effectiveness of all enspells via a path specifically for RDM's.
Perhaps, trigger X Enspell x a set amount of times. This would be similar to the debuff types of trials.
Each stage could require. Both Enspell 1 and Enspell 2 amounts of trigger per element.
I choose daggers primarily since RDM have good skill in both swords and daggers, but RDM daggers have been under utilized so far in trials. Though, we are not listed under dagger trials, this could easily been worked out.