For anyone who doesnt know it by now, Legion adds another item modifier which stacks with warforged (+10 ilvls) and the others.
Titanforged is similiar to Baleful items from Tanaan or WoD mythic dungeon drops, where the item level range is +5 - +75 in intervals of 5.
Any item dropped in Legion, be it leveling quest rewards, world boss loot, heroic/mythic dungeon or raid loot can be titanforged, warforged, have an extra socket and/or a tertiary stat now.
This means that 825 heroic dungeon loot could potentially end up as ilvl 900 (above normal mythic raid loot).