Beta Titan: Rodan

Bio-Volcanic Nature. Rodan absorbs any fire damage and converts it into stored energy, that it uses to increase its temperature and start volcanos. He can  store  as much energy as he has max hp. At the beginning of a fight, Rodan will usually start with max amount of stored energy.

Cyclone Flying. Everything under Rodan musst make a dc 20 con save, or take 2d10 bludgeoning damage, or half as much on a success.

Fire Radiation. Everything starting its round in 100 feet radius of Rodan musst make a dc 22 con save or take 10 fire damage, or half as much on a success. Stored energy can be used at the beginning of Rodans turn, increasing the damage by 1 for every stored energy used. The damage buff stay until the beginning or Rodans next turn.

If a creature hits Rodan with a melee attack, it musst make a dc 24 con save, or take 5d10 fire damage or half as much on a success.

Titan Power. Rodans attacks count as magical to overcome resistances. 

Legendary Resistance (3/Day). If Rodan fails a saving throw, it can choose to succeed instead.

Multiattack. Rodan attacks twice with his claws and once with his beak.

Claw Attack. Melee Attack: +13 to hit, reach 30 ft., 1 target. Hit: 15 (1d10 + 10) [slashing] and 15 (1d10+10) [fire] damage. If the attack hits, the target musst make a dc 22 strength save, or be grappled. It has two talons to grapple with.

Beak Attack. Melee Attack: +14 to hit, reach 30ft., 1 target. Hit: 27 (5d4 + 15) [piercing] damage and 25 (2d10+15) [fire] damage.

Spawn Lair (1/day). Rodan can spend 50 stored energy to create an volcano at its desired spot, making it Romans new lair. The ground explodes in a 900 ft. radius and deals 33d10+30 fire damage. After that, the ground is turned to molten rock and that is Rodans new lair. 

Beak Attack. When grappling a target, Rodan can make a Beark attack on it as a bonus action.

At the end of the turn of a creature Radon can make a legendary action.

Legendary Action Name (Costs 1 Actions). Radon moves at full speed.