The Truth Is, I Love You ♥
Join Date: Jun 2008
Location: Memories Pokemon: Mums
If you want Siren Song to 1hko, you need around 50k+ HP. Currently I'm not active in TO so I can't check for you what my damage is with my stats.
You will eventually need to master Power Blow, Dodge Master, Mana Reflector, Volley Kick, Sturdy Shield, and Shield All. Mastering Dodge Master is an obvious reason [ more HV ].
Mastering Power Blow and Volley Kick will increase your 2-step damage as well [ the amount increase isn't like 1k+ but it's still a nice increase ]. Mana Reflector to reflect more magic damage. Sturdy Shield and Shield All for more DP, which can help your Siren damage a little if you learn it in the future.If you melee [ with elemental gears ] and use skills, check if your VK can 1hko. If it can't, you should master it.
If you plan to ignore mastering those skills, you could learn Sumo Suit since you already met the two skill requirements.