Need help/advice with setting up devotions for a Fire Shieldbreaker (Vire's Might + Mortar)

I’m thinking of running a build like this: https://www.grimtools.com/calc/wV188MM2

I haven’t planned my gear yet so for now I’ll be using mostly faction gear plus any decent finds I have that can boost fire damage and have CDR to make VM more spammable. I likely will not be using a shield to make way for that MI off-hand (Zarthuzellan’s Archive) that reduces VM’s CD (don’t have it yet, but once I do I will remove VM’s transmuter). 2handers are not considered.

For devotions, I got Magi bound to VM and Ulzuin’s Torch to Mortar. I have 22 unspent devo points left but was unsure of where to put them. I assume I need to use them on defensive stars/constellations with resist, health regen, etc. anything that helps with survival. This is a mobile build though so I’m not sure if it’s worth spending those points on survivability than more damage (if going for more damage, which other stars/constellations should I go for?).

Any advice is appreciated, and thanks in advance!