Tower of Doom is a new event as of patch 4.1 of Title Update 11 and appears like it will run every fourth week.
Functions similar to delves - you are locked into a team color - All troops must use this color. Hero's are not color restricted.
Unlike delves troops who die come back in the next battle.
Like most weekly events you are given four sigils per day - and can buy more with Gems in the store.
Each floor in the tower of doom offers several battles. Winning a battle unlocks a scroll.
There are 11 types of scrolls (Thanks to Evil Genie for this info from the patch notes)
- Armor Scroll - Give Guild Armor Boon
- Life Scroll – Gives Guild Life Boon
- Attack Scroll – Gives Guild Attack Boon
- Haste Scroll – Gives a Doom Sigil
- Magic Scroll – Gives Guild Magic Boon
- Luck Scroll – Gives 2 bonus points towards the Guild’s Doom total
- Power Scroll – Gives 1 to all Guild Boons
- Unlock Scroll – Unlocks the Boss Room containing the Doom on this level
- Heroism Scroll – Immediately defeat the Doom for this level and move on to the next level (you may collect these and use them anywhere in this tower)
- Fireball Scroll – Immediately defeat a non-Boss Room (you may collect these and use them anywhere in this tower)
- Colored Forge Scroll – Used to temper Doomed Weapons of the matching color
In order to get this achievement you must defeat the Doom (Boss) on six floors - the Boss fight will be Level 60.
Extra Tip - Confirmed by my guild:
Unlock scroll locations are the same on each floor for everyone in your guild. - Communicate in chat and you can help others progress faster through each floor of the Tower of Doom - saving sigils.
Extra tip from Evil Genie:
If you find a Luck scroll, this also counts as 2 of the six Dooms you need to defeat for the achievement. I had beaten the first five floors, then found a Luck scroll to boost my total to 7 and the achievement popped.