I've never actually tested it, but according to the patch notes it should scale off your highest crit.
From Patch Notes v1.6.5
Other Major Gameplay Changes
- Synergy abilities now scale off your highest stats that are either stamina or magicka based.
- Ultimates and Synergy abilities now always scale of your highest Critical Strike stat instead of just your Spell Critical Strike.
- Abilities that cost magicka will now always scale off your magicka, spell damage, and spell critical strike stats.
- Abilities that cost stamina will now always scale off your stamina, weapon damage, and weapon critical strike stats.
Hello.w3ng_vgeb17_ESO wrote: »My test shows that e.g. the sorc's Overload ultimate scales with weapon damage.
When I increase my weapon power, then the tooltip for the Overload attacks increases.