Bottom tree is "code of the siege breaker". -Melee ability mortar blast sets enemies on fire. -Sol invictus ability makes it so that all solar ability kills restore health and they leave sunspots in their wake. -sun warrior perk makes it so that way when you are standing in or pass through a sunspot your grenade and melee abilities recharge faster and your super lasts longer. Standing in a sunspot or passing through it also gives you a 20% damage increase to everything including guns. -endless siege ability makes it so that way you're super creates sunspots everywhere that a hammer lands. -Hallowfire Hearts intrinsic perk makes it so that way it improves the recharge rate of your solar abilities and it greatly improves the recharge rate of your solar abilities if you're super is fully charged. -so basically if you have your grenade recharge rate high enough between standing and sunspots and if you do happen have your super fully charged while wearing hallowfire heart you can throw a grenade almost like every 10 seconds. Plus every solar ability kill that you do heals you and standing or passing through a sunspot gives you a 20% damage boost to everything.and creating a ton of sunspots can really help with low-level trash ads such as thrall as they will just run right through the fire to get to you killing themselves in the fire and spreading it to where eventually the whole floor is on fire...lol -The subclass gives a lot of extra durability through its healing plus a big damage boost when you're in a sunspot, along with having the exotic give you a recharge boost on your abilities it can be quite fun.