Do people mind frickken-9-year-necros around here, as long as the post is useful? I was looking for the answer to this myself and found this topic, and since I'm currently screwing around with a no-mitigation-no-leech seraphim (who uses willpower, lightsabers, and Warding Lore with the Warding Energy buff) I figured I might be of some use (not to the dude with the question, they've probably died of old age by now, but anyone else who might have the same one and see it). I couldn't find this information on the wiki either for when I was making the character, so I just *hoped* I'd be alright, so far it's worked.
Given all my points in Strength and 420 Willpower, I have 71,510 Energy Shield. If I move all 178 points I have over into Willpower for a total of 640 (there's some survival bonus in there) I have a total of 93,437 Energy Shield. That's 21,927 more shield, or 99.66 more Shield per Willpower at level 109. Keep in mind that's with mastered Warding Lore for 150% someodd more and the Art Mods that give extra percentages to max shields, so I don't know the absolute base amount per point and I'd never be able to figure out the hundred-character-formula for how it works anyway (Algebra II was a LONG time ago). As an interesting side note, my total shield goes up by another 87,192 to 180K someodd (EDIT: with Divine Protection. This sentence didn't make any sense at all before). With as hard as I remember some bosses hitting, it'll definitely be necessary on a no-mitigation-no-leech run. How does the Temple Guardian compare, with their supposed regen-in-combat? Never tried one.
My last seraphim had no points in Warding Lore and specced for reflection mods and Vitality, and I remember her level being in the hundreds (with 200 warding runes read) and having something like 5,000 shield, which was totally useless. Normal enemies blew it off in two spells... so investing in your Energy Shield will definitely make a huge difference.
Anyway, if people hate these necros yell at me and I won't do it again. IT'S NOT NECROMANCY IF INFORMATION NEVER DIES