5th Team member for Abyss
Looking to tackle easy path in Abyss w/ my all 5* R5 Four Horseman but struggling to fill the 5th spot.  Following is the breakdown of options:
Max 5* Quake: 3 evades per fight for everybody.  Will help build Aegon combo.
R4 5* Proxima: will help w/ Aegon build and than give Aegon’s furies an additional 25% potency.
R4 5* Heimdall: prevent knockout once per fight. 
R2 6* max sig Morningstar:  can help with Duck Fights... maybe others?  Gives Doom energy damage when nullifying.