Lines are quoted from the official notes; buff/nerf tags are auto-classified from the numbers and can be wrong. Covers the 14 most recent Dota 2 patches PatchMeter has fetched.
⇄adjustDevourNow the default cast gained on learning Devour is the one that grants abilities of devoured creeps, and alt-cast state keeps the ones that Doom currently has
▲buffDevourCooldown decreased from 70s to 66s
⇄adjustDevourNow upgraded with Aghanim's Shard
▲buffScorched EarthRadius increased from 600 to 666
⇄adjustScorched EarthNow also provides Doom with 7/8/9/10 bonus health regen
✕removedScorched EarthNo longer upgraded with Aghanim's Shard
▲buffInfernal BladeStun Duration increased from 0.6s to 0.66s
▲buffDoomDamage per second increased from 25/45/65 to 25/45/66
⇄adjustDoomAghanim's Scepter now also applies Break to affected enemies
✕removedDoomAghanim's Scepter no longer increases damage per second by 15
▲buffTalentsLevel 15 Talent Scorched Earth Movement Speed increased from +5% to +7%