I got it. then, Since SE doesn't want to make RDM stronger in SOLO situations.

To keep the RDM enfeebling from being to strong solo. Add a trait that multiplies their magic based on the amount of players in their party or alliance. If it's a job ability It would create a ritual circle on the ground that amplifies the RDMs magic using the alliance or party members as catalyst for their power. This is liken to people holding hands in prayer or when doing a rituals.

Warlocks and Witches have done this in reality and it fits the "Warlock" description.

Trait:
Ritual Tactics I
LVL 50
Can benefit from up to 6 party or alliance members.

Ritual Tactics II
LVL 75
Can benefit from up to 12 party or alliance members.

Ritual Tactics III
LVL 99
Can benefit from up to 18 party or alliance members.

This way they won't get that god like power in a solo situation. It fits the self enhancement well, as it doesn't boost allies or make them over powered solo. It boost the RDM magic based on the number of allies they have in party or alliance. By having this boost the allies have enfeebles that actually do something worth giving at least one rdm a spot in the party/alliance.