Solven, Swamp Progenitor

Menace
4{b}{g}, {t}, Sacrifice another creature: Regenerate Solven.
{5}, {t}: Tap all opponent Black lands, they do
not untap during their next untap step.
If all 5 Titans are on the battlefield together,
Scry 1, then give them all +2/+2 counters until
one of them leaves.
Once a god, now a mere underling.