Unleash Hell! (Supporting Fire) has no real support on the skill tree

I didn't even notice this until now but since this skill is a 'minion' but NOT a companion, you can't really build into it except attribute stacking (kinda boring?). The closest minion nodes are some 20-ish points away from the starting position and really not that good of a trip.

I think the skill would fit more neatly into this side of the tree by making it a companion instead (just give the node +1 max companion, so you'll still be able to have another "normal" companion like any other character). Then the attribute scaling can be lowered or removed, as I don't think you'll allocate this node at all, if you're not trying a companion build. Especially, since the preceding small node is '20% minion damage'.

Additionally, this would remove the anti-synergy with the "Lifelong Friend" notable, which usually gives you a big revive speed boost if you only have companions but since "Unleash Hell!" currently gives you a permanent non-companion minion, it basically disables that node.

Also, if you read 'artillery', you usually don't think of a bunch of archers. Instead, you'd think of heavy machinery, which is usually emplaced and operated by several soldiers, like catapults, onagers, ballistas and similar. It'd be a great improvement if there would be some heavy bolts raining down in the later waves and maybe even a explosive payload on the last wave. Even just for the feeling (if you ever played Helldivers 2, you can probably relate).

If this skill could wipe a white or even blue pack every 40 seconds, I believe that'd be perfectly fine. You can already do that with gem skills on shorter cooldowns with faster activations.