How to beat Heroic General Cobaltann with a lvl 20 team

I just beat Heroic General Cobaltann yesterday and after giving some tips to my guild mates, I thought I would share them here too since there aren't many guides online. This is particularly for F2P or booster players who are severely underleveled but I believe most players at this stage are mostly lvl 20 on average, more or less.

Jaina - At first, I wanted to try using Living Bomb but it wasn't sustainable due to my lvl 20 team. So I switched to blizzard to get rid of the whelps and rime ritual skeletons. With Jaina's frost attack, a banshee is not needed and don't send too many minis on the bridge, otherwise you would get a blizzard. A firehammer can also attack a tower from the bridge so take that advantage if you can coz it will make things easier. EE is there as a distraction to Cobaltann or tower.

Murkeye - Additional tidehunters spawned by your minis after Murkeye aren't affected by the cold, so it's best to spam as many times as you can. I could have used blizzard but I thought poly gold fleece is a good counter to huntress, gargoyle and other mobs to get that extra 1 gold. The enemy that got hexed are vulnerable to elemental so a chimaera is perfect. Sir Quilliam and EE are baits so that your tidehunters can DPS quickly.

Rend - Personally, I think using Rend was the easiest. His dragon fire splash dmg takes care of whelps and gargoyle easily, alongside chimaera with -1 gold. The iron miner can take other gold veins when possible, and the rest of your range minis can DPS. Rend can also be a tank when he reaches Cobaltann.

Grom - The reason to use Grom is activating bloodlust and also a counter to the huntress, troll or take on Cobaltann. I also experimented using vampirism Cheat Death to keep the troll, firehammer and shaman (these trio are invincible) alive as long as possible. The AI will throw a blizzard occasionally so with the right timing, your trio will survive with cheat death and reach Cobaltann. They will DPS while EE distracts the boss. Whelps also help to wipe out AI rime ritual skeletons and whelp eggs together.

Thalnos - Thalnos benefits with vampirism cheat death more coz of his auto level up per spell cast and regain HP while attacking when nearing death. If you are careful enough, your first Thalnos will be over leveled by the time he reaches Cobaltann, and you will probably have a second Thalnos spawned already. Alternatively, you can also use execute instead of arcane. Shaman is there to keep Thalnos alive and cast armor.

Additional notes - Taking over the tower will make things easier but it takes too long. If you can push through on the bridge, then just do it. - Always spawn your minis at the right side of the staircase to clear the whelp eggs easier (especially huntress) and avoid getting hit by the tower. - Aslong as you have frost attack or firehammer, you can yeet that gargoyle without a banshee.