ToME: the Tales of Maj'Eyal

I've made a Shalore sun paladin thinking that timeless would be awesome with flash of the blade level 4 block all ability, but it seems this doesn't work at extending the duration of it. Is it a bug or intended? First time making a serious Shalore so not sure how timeless really work.

The positive effect duration extension on Timeless is limited by the remaining duration of the positive effect in question, so no, you're not supposed to be able to get 6 turns of invulnerability from Flash of the Blade.

Timeless specifically does not affect "other"-typed status effects, which includes the shield from Flash of the Blade.