Guys, the event dragon lets Thaniel hit the HP check for HBH, since 30% HP is the same HP buff MUB Poseidon gives, which makes the fight SIGNIFICANTLY more F2P friendly. It's not as F2P friendly as HMS which can literally be done with Euden + Pele, and you need hefty dojo investments (26/26 assuming maxed water facility as well), but it's a big step up from before this event when the only possible dragon options were MUB Poseidon and Levi.
While you do miss out on Strength, Thaniel only contributes around 2% of HBH's total health with MUB Poseidon, so it will only matter if you timeout the fight with 2% HP remaining.