Bellona Joust Damage

As I said before I tend to keep my skills all evenly matched. They are all useful when you build attack speed.

Shield bash: reserve this attack for the initiate and the kill confirms. If you use it first you get that boost forward to attack plus the basic attack his IMMEDIATELY after allowing frostbound and the shield bash to slow a lot.
If you are up against a very damaging opponent then keep the shields out until you get to half health, then whip them, you will be surprised how much damage you ignore with the shield's block stacks.

Hammer: this is best used with your team around. yes, it can confirm kills and is good for it but try to focus on grouped up enemies, if you happen to hit all three, then some unlucky god will take 50% EXTRA damage. Swinging the hammer in these groups is devastating, hitting all enemies and minions in your range with a slow. This is not recommended as a primary attack except against jungle camps because it is quite a bit slower than other options.

Whip: primary go to weapon for Bellona, it attacks fast and gives HP. If you are attacking the bull demon, or the tower don't use anything else. Use the whip to disarm hunters in engagements, while still hitting your primary target, hunters hate not being able to attack and usually will dash or jump away if they feel threatened, the other option is they will begin to focus their abilities on you allowing you to shred them with the whip while they wait for cooldowns. Never use the whip if it is not going to support, like against a non-basic attacking mage (chronos, sol, etc.) instead use the shield bash on them, mages are not typically good against slows and will retreat fast if they are threatened.

All this and you should be able to dislocate at least 1 of the enemy team allowing for a team kill, you may have damaged someone else pretty good that is when you ult and get the kill confirm.

Level up the skills anyway you see fit, all of the skills have great use with attack speed so I usually try and keep them evenly matched.

If you are in a joust as a Warrior and have a good solid damage team or a heavy guardian then this Bellona build works well to dismantle all types of enemies.

Main Role: Initiate then support, kill confirm when possible

With this build I do best leading the charge, then when my team has arrived to support me I support the fight by focusing on disarming basic attackers while others are being focused by my team, once damage has been dealt around I can usually get a kill confirm with a quick shield bash tower dive.
This build is NOT tank like, it is a glass cannon in the beginning of the game but with Asi and Qin, the whip deals heavy damage while keeping me alive while at low HP. I have had a 90% success rate with 1 on 1 encounters because of them.

The next role Bellona does well at is at level 8, she can solo the bull demon king. As long as you have Asi, ATK spd boots, and qin and spin around him while whipping (to avoid the ground pound) he falls *somewhat* slowly but easily. While that doesn't sound ideal, leaving 2 team mates in the lane while 1 player gets the demon even for just the tower is a huge advantage when it comes to pushing it down quickly. We can usually get the tower within a minute after slaying the bull demon.

In late game she is an absolute beast. Focus your attacks on one target constantly and they will melt away. Double life steal is my favorite allowing more sustain. Always remember to disarm hunters before engaging your target it will more than likely cause them to retreat to far to help the guardian, warrior or who ever you are assaulting.

As for the relic options, I find it best to stay supportive to your team and self with Med first, even against an Ares or Hades who's ultimates hurt and CC. Why? Well after the 3rd item built I often find that unless I am low, they typically do not want to ult me, Ares can CC me to him but I usually rip his health away for doing so. I can also time my ult against his (which without cooldowns is shorter than his with cooldowns) and jump myself to an unwanted position like, against his mage. I use the Bracers of undoing for tower dives, when I get kill confirms inside the tower it usually takes a couple seconds which can hurt sometimes, being able to undo up to 5 secs of it really makes getting out alive easy. And thorns I found useful against a team with 2 hunters and a guardian. I got hide of the lion and thorns and when the disarm would lose it's effect all they wanted to do was shoot me so I pop thorns and they destroy themselves.