Sigil Ideas: You asked for it...

Sigil of the warriors spirit: Gives absorption and strength buffs, high upkeep toll. T4-6.

Sigil of shadow walking: Gives invisibility, slowness, maybe weakness, and might make the user burn in daylight, 50 ish LP a second. T4.

Sigil of the soul sear: Right clicking on a player tells the user if the target has anything bound to there soul. Might also read the network size. Would be nice if other players can't see you holding it(Basicly, a way to find blood mages without them just telling you. Let the hunt begin). T2.

Sigil of the altar: Basically an upgrade to the divination sigil. Gives more information about the altar(I'm thinking stuff like the total cost of the transmutation, how long it would take if it never lost progress, and more information about how much faster it is due to speed runes or bonuses from sacrifice runes. It is just the altar builders dream tool.). 100LP per use(Small price to pay for all this) and removes the ability to read the soul network. T3.

Sigil of the Shell: Forms a dome of spectral blocks around the player. Basically, an emergency panic sigil. Costs a little more then the phantom bridge. T4.

Sigil of the statue: Shoots a projectile that gives the target a strong slowness debuff and resistance. They can barely move for about ten seconds, giving the user a chance to run, while the target can barely be touched. T5 or 6.

Sigil of the Barrier: Creates a wall of spectral blocks two blocks in front of the player that lasts thirty seconds. Used for defense and building(I'm starting to see a pattern here). T3.

Sigil of dimensional shift: Right clicking on a block will temporarily remove a chunk of blocks(similar to TC portable hole, but larger width and shorter range. T5 or 6.

Sigil of ender severance: Cuts off endermens connection to the end, stopping there teleportation. Passive cost with a 9x9 square centered on the user(If there isn't a direwolf reference in the flavor text, I will shun you for ruining a perfect opportunity). T4 or 5.

Sigil of soul remembrance: Saves the position, health, and potion effects at the time of use(But not inventory). After the timer runs out, they player is returned to the location and it restores any and all effects. T6.

Sigil of soft touch: When right clicked on a block, it acts like the block was broken with silk touch. T4.

Sigil of forbidden knowledge: Allows the user to convert LP to XP. T4-6.