Im preparing to run Storm Kings Thunder merged with Tyranny of dragons for a level 1-20 campaign.
Will be using the 5.5e and therefore the new monster manual.
I really like that the hill giant has a version of the Topple Weapon Master (prone on melee hit) and have been thinking about adding weapon masteries to the other to martial focused Giants, Frost and Fire.
I would like to add Cleave to the frost giant and Graze to the fire giant.
For Cleave I would remove the once per turn, thematically the attack is like a sweeping attack hitting multiple creatures with one stroke.
For Graze I’m think that the damage would be equal to the fire damage of the Fire Giants Flame Sword attack only. Thematically this would be that the heat from the sword is so intense that even though the attack missed you, you take some damage.
What do you think in, how much of an impact would this have on the CR of the Frost and Fire Giant?
Rules for reference.
Cleave PHB p214
If you hit a creature with a melee attack roll using this weapon, you can make a melee attack roll with the weapon against a second creature within 5 feet of the first that is also within your reach. On a hit, the second creature takes the weapon's damage, but don't add your ability modifier to that damage unless that modifier is negative. You can make this extra attack only once per turn.
Graze PHB p214
If your attack roll with this weapon misses a creature, you can deal damage to that creature equal to the ability modifier you used to make the attack roll. This damage is the same type dealt by the weapon, and the damage can be increased only by increasing the ability modifier.