I was playing against Teclis and the other player had said that Teclis’ spell could be measured from both Teclis and also the umbral spell portal. The way I understand the spell portal is that it just allows the caster to cast from the portal as if it were the caster, similar to how using the Trog to cast spells from Kroak works. He said he seen battle reports of people measuring from both the spell portal and Teclis but to me that seems as if they’re just playing wrong? Is there an faq or something that defines this interaction?
Yes, that's correct. There's NOTHING in Teclis warscrolls that allows that. I don't know about FAQ or anything, it could be... but it's up to Teclis' player to show such a proof that goes against the rules of casting and Umbral Spell portal. "I've seen it on internet" IS NOT a valid evidence. I call BS on that.
You have to measure the range from one or the other, cant do both. The rules of spellportal say this. You measure from the spell portal
that'd be a ridiculously effective way to increase the area covered by AoE spells. There's no way that's legal. Also, every other mechanic, like a troglodon, or our Kroak with his AoE, doesn't do that. So yeah, unless Teclis has some super special rule hidden somewhere that we don't know about he's saying nonsense
It is measured form one of the other. The only exception are spells that measure a range from one point and then draw a line of effect back to the caster's base. Those could be range measured from the portal and then drawn backwards to the caster's base.