Thingamabob (14 Green/Blue) Legendary Artifact
Deal [Magic + 4] damage to an enemy and adjacent enemies, boosted by Submerged allies. [7x]
Three Sisters (13 Blue) Mythic Polearm
Deal [Magic + 5] heavy splash damage to an Enemy, boosted by all Blue Allies and Enemies. If an Enemy dies, give 3 Magic to all Allies and Submerge them. [4x]
Heavy splash damage does 100% damage to main target and 75% to adjacent targets. Right now my Thingamabob has 23 magic, so it does 27 damage to main target and 27 to adjacent. That’s 81 damage. The damage is boosted only by submerged allies, but it’s 7x for each submerged ally, so that’s a max of 28 bonus damage (I’m assuming it can count itself even though it loses submerged after casting, especially since it re-submerges you). That’s 55 damage to the main target, and 55 to each other: 165 total.
Three Sisters is boosted by blue allies and enemies. That’s a max of 8 boosts of course, 4 for each, that’s 32 extra damage. But, it’s only 24 extra damage for the adjacent targets. That’s 27+32 = 59 main target, and 20+24=44 for side targets. That’s 147 damage total, 18 less than Thingamabob. However, it’s far more likely to max out the boost on Thingamabob with 4 submerges than to have 8 blue boosts.
Furthermore, because Three Sisters is only blue mana, you’d have to either front line with it, or bring a non-blue ally with it, reducing the boost.
The weapon upgrades too: Thingamabob creates a blue gem, submerges you, drains 3 mana from first enemy, and gains 1 magic (3 more damage total).
Three Sisters you gain 4 life, cleanse yourself, deal 5 damage to second enemy (typical for polearm), gain 1 magic, and give all allies 2 life. But the class itself is a back line class. There is nothing in there for being in the front line, which means it’ll be hard to actually fill your mana when everyone else is getting blue before you. At least Thingamabob has green mana as well so you can have a source from somewhere.
I’m having a hard time understanding how this is a mythic weapon.