The meta about starting on the side, are years old.
When you start on the side platforms, he will guarantee teleport to middle platform, and you have full control of where he teleporting.
If you start middle platform, he might go right and he might go left, at random, which can cause some issues.

Anyway, time to move on, and I'm here to teach you all new meta, starting easy with this Valkyn THINGIE! Yeah I said thingie, its a nice word. Start using it, new meta.

Start middle platform first. You will earn like 15 sec dps time, specially now in the melee stamina meta, since it takes time to taunt him towards the edge platforms (vodka shot every time you read platform). Burn him down before he teleports. The dps have been high enough for a long time, its nothing new. Go one healer and 3 dd's, or 4 dd's. No tank needed in coa. No tank needed in crypt of hearts. No tank needed in WGT. But you still need the buffs, combat prayer, warhorn, aether, spc etc (I just wrote etc because I was out of options and wanted to sound like I know stuff (I do know stuff but you know what I mean (3 parenthesis is one sentence, is that legit? ))).

There you go, start doing it, no need to be scared anymore. You are all welcome, and I am happy to share my knowledge. So now we can all start doing this without me having to tell people in group chat to start middle platform and explain why, its an official meta now.

Have a nice day